Generator & Regulator: Other Lexus SC I

Except ES300

Apply 22-lb. (10-kg) force to top belt run. Belt tensioner should move downward, and pointer on belt tensioner should fall within area "A" (used belt) or area "B" (new belt). (Scheme 14)or (Scheme 16). If pointer does not fall within specified area, replace belt or belt tensioner as necessary.

Scheme 14

Scheme 15

Scheme 16

ES300

Check belt tension using Burroughs Tension Gauge (BT-33-73F ) at longest belt run. Adjust belt if tension is not as follows.

1. New Belt - 170-180 lbs. (77-82 kg)
2. Used Belt - 95-135 lbs. (43-61 kg)

Scheme 17

Scheme 18

Scheme 19

Scheme 20

Scheme 21

Scheme 22

Scheme 23

Scheme 24

Scheme 25

1. Check battery electrolyte level and voltage Check the electrolyte quantity of each cell. If under the lower level, replace the battery (or add distilled water if possible). Check the charging system. Measure the battery positive voltage between the terminals negative (-) and positive (+) of the battery. Standard voltage: At 20° C (68° F) : 12.2 - 12.9 V HINT: Before measuring the voltage, turn the ignition switch to LOCK and turn off the electrical systems (headlight, blower motor, rear defogger etc.) for 60 seconds to remove the surface charge. If the vehicle has been running, wait 5 minutes or more after the vehicle stops before measuring the battery positive voltage. If the voltage is less than specification, charge the battery.
2. Check battery terminals, fusible link and fuses Check that the battery terminals are not loose or corroded. Check the fusible link and fuses for continuity. Fusible link: Main 2.0L H-Fuse: ALT 100A M-Fuse AM1 40A Fuse: AM2 30A IG2 7.5A GAUGE 15A ALT - S 7.5A
3. Inspect drive belt Visually check the belt for excessive wear, frayed cords etc. If any defect has been found, replace the drive belt. HINT: Cracks on the rib side of a belt are considered acceptable. If the belt has chunks missing from the ribs, it should be replaced. Using a belt tension gauge, measure the drive belt tension. Belt tension gauge: Nippondenso BTG-20 (95506-00020) Boroughs No. BT-33-73F Drive belt tension: New belt 175 ± 5 lbf Used belt 115 ± 20 lbf If the belt tension is not as specified, adjust it. HINT: "New belt" refers to a belt which has been used less than 5 minutes on a running engine. "Used belt" refers to a belt which has been used on a running engine for 5 minutes or more. After installing a belt, check that it fits properly in the ribbed grooves. Check with your hand to confirm that the belt has not slipped out of the groove on the bottom of the pulley. After installing a new belt, run the engine for about 5 minutes and recheck the belt tension.
4. Visually check generator wiring and listen for abnormal noises. Check that the wiring is in good condition. Check that there is no abnormal noise from the generator while the engine is running.
5. Check discharge warning light circuit Warm up the engine and then turn it off. Turn off all accessories. Turn the ignition switch "ON". Check that the discharge warning light is lit. Start the engine. Check that the light goes off. If the light does not go off as specified, troubleshoot the discharge light circuit.
6. Inspect charging circuit without load HINT: If a battery/generator tester is available, connect the tester to the charging circuit as per the manufacturer's instructions. If a tester is not available, connect a voltmeter and ammeter to the charging circuit as follows. Disconnect the wire from terminal B of the generator, and connect it to the negative (-) probe of the ammeter. Connect the positive (+) probe of the ammeter to terminal B of the generator. Connect the positive (+) probe of the voltmeter to terminal B of the generator. Ground the negative (-) probe of the voltmeter. Check the charging circuit as follows: With the engine running from idling to 2,000 rpm, check the reading on the ammeter and voltmeter Standard amperage: 10 a or less Standard voltage: At 25° C (77° F): 14.0 - 15.0 V At 115° C (239° F): 13.5 - 14.3 V If the voltmeter reading is more than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the voltage regulator and generator as follow: With terminal F grounded, start the engine and check the voltmeter reading of terminal B. If the voltmeter reading is more than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the generator.
7. Inspect charging circuit with load With the engine running at 2.000 rpm, turn on the high beam headlights and place the heater blower switch at "HI". Check the reading on the ammeter. Standard amperage 30 A or more If the ammeter reading is less than the standard amperage, repair the generator HINT: If the battery is fully charged, the indicator will sometimes be less than standard amperage.

M.Y. 1996

Scheme 26

Scheme 27

1. Check the electrolyte quantity of each cell. Maintenance-Free Battery: If under the lower level, replace the battery (or add distilled water if possible). Check the charging system. Except Maintenance-Free Battery: If under the lower level, add distilled water.
2. Except Maintenance-Free Battery: Check battery specific gravity Check the specific gravity of each cell. Standard specific gravity: 1.25-1.29 at 20° C (68° F) If the specific gravity is less than specification, charge the battery.
3. Maintenance-Free Battery: Check battery specific gravity After having drive the vehicle and in the case that 20 minutes have not passed after having stopped the engine, turn the ignition switch ON and turn on the electrical system (headlight, blower motor, rear defogger etc.) for 60 seconds to remove the surface charge. Turn the ignition switch OFF and turn off the electrical systems. Measure the battery voltage between the negative (-) and positive (+) terminals of the battery. Standard voltage: 12.5-12.9 V at 20° C (68° F) IF the voltage is less than specification, charge the battery.
4. Check battery terminals, fusible link and fuses Check that the battery terminals are not loose or corroded. If the terminals are corroded, clean the terminals. Check the fusible link, H-fuse, M-fuse and fuses for continuity.
5. Inspect drive belts Visually check the drive belt for excessive wear, frayed cords etc. If any defect has been found, replace the drive belt. HINT: Cracks on the rib side of a drive belt are considered acceptable. If the drive belt has chunks missing from the ribs, it should be replaced. Using a belt tension gauge, measure the belt tension. Belt tension gauge: DENSO BTG-20 (95506-00020) Boroughs No. BT-33-73F DRIVE BELT TENSION New belt 175 5 lb.ft Used belt 115 20 lb.ft If the belt tension is not as specified, adjust it. HINT: "New belt" refers to a belt which has been used less than 5 minutes on a running engine. "Used belt" refers to a belt which has been used on a running engine for 5 minutes or more. After installing a belt, check that it fits properly in the ribbed grooves. Check with your hand to confirm that the belt has not slipped out of the groove on the bottom of the pulley. After installing a new belt, run the engine for about 5 minutes and recheck the belt tension.
6. Visually check generator wiring and listen for abnormal noises Check that the wiring is in good condition. Check that there is no abnormal noise from the generator while the engine is running.
7. Check charge warning light circuit Warm up the engine and then turn it off. Turn off all accessories. Turn the ignition switch "ON". Check that the charge warning light is lit. Start the engine. Check that the light goes off. If the light does not go off as specified, troubleshoot the charge light circuit.
8. Inspect charging circuit without load HINT: If a battery/generator tester is available, connect the tester to the charging circuit as per manufacturer's instructions. If a tester is not available, connect a voltmeter and ammeter to the charging circuit as follows: Disconnect the wire from terminal B of the generator and connect it to the negative (-) probe of the ammeter. Connect the positive (+) probe of the ammeter to terminal B of the generator. Connect the positive (+) probe of the voltmeter to terminal B of the generator. Ground the negative (-) probe of the voltmeter. Check the charging circuit as follows: With the engine running from idling to 2,000 rpm, check the reading on the ammeter and voltmeter. Standard amperage: 10 A or less Standard voltage: At 25° C (77° F): 14.0 - 15.0 V At 115° C (239° F): 13.5 - 14.3 V If the voltmeter reading is more than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the voltage regulator and generator as follows: With terminal F grounded, start the engine and check the voltmeter reading of terminal B. If the voltmeter reading is more than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the generator.
9. Inspect charging circuit with load With the engine running at 2,000 rpm, turn on the high beam headlights and place the heater blower switch at "HI". Check the reading on the ammeter. Standard amperage: 30 A or more If the ammeter reading is less than the standard amperage, repair the alternator. HINT: If the battery is fully charged, the indication will sometimes be less than standard amperage.
10. Reinstall engine under cover

Scheme 28

Scheme 29

Scheme 30

Scheme 31

Scheme 32

Scheme 33

Scheme 34

Scheme 35

Scheme 36

Scheme 37

1. Check battery electrolyte level and voltage Check the electrolyte quantity of each cell. If under the lower level, replace the battery (or distilled water if possible.). need to check the charging system. Measure the battery voltage between the terminals negative (-) and positive (+) of the battery. Standard voltage: At 20° C (68° F): 12.7-12.9V HINT: Before measuring the voltage, turn the ignition switch oFF and turn off the electrical systems (headlight, blower motor, rear defogger etc.) for 60 seconds to remove the surface charge. If the vehicle has been running, wait 5 minutes or more after the vehicle stops before measuring the battery voltage. If the voltage is less than specification, charge the battery. HINT: Check the indicator as shown in the illustration.
2. Check battery terminals and fuses Check that the battery terminals are not loose or corroded. If the terminals are corroded, clean the terminals. Check the fuses for continuity. H-fuse: ALT 100A AM1 40A Fuse: AM2 15A ALT SENSING 7.5A GAUGE 15A
3. Inspect drive belt HINT: A belt tensioner is used, so checking the belt tension is not necessary. Visually check the drive belt for excessive wear, frayed cords, etc. If necessary, replace the drive belt. HINT: Cracks on the rib side of a drive belt are considered acceptable. If the drive belt has chunks missing from the ribs, it should be replaced. The drive belt tension can be released by turning the belt tensioner clockwise. Check the belt tensioner operation. Check that the belt tensioner moves downward when the drive belt is pressed down at the points indicated in the illustration with approx. 98 N (10 kgf, 22.0 lbf) of force. Check the alignment of the belt tensioner pulley to make sure the drive belt has not slipped off the pulley. If necessary, replace the belt tensioner. Check that the arrow mark on the belt tensioner falls within area A of the scale. If it is outside area A, replace the drive belt. HINT: When a new belt is installed, it should be within area B. If not, the drive belt is not installed correctly. After installing a belt, check that it fits properly in the ribbed grooves. Check by hand to confirm that the belt has not slipped out of the groove on the bottom of the pulley.
4. Remove engine under cover
5. Visually check generator wiring and listen for abnormal noises Check that the wiring is in good condition. Check that there is no abnormal noise from the generator while the engine is running.
6. Check charge warning light circuit Warm up the engine and then turn it off. Turn off all accessories. Turn the ignition switch ON. Check that the charge warning light is lit. Start the engine. Check that the light goes off If the light does not go off as specified, troubleshoot the charge light circuit.
7. Inspect charging circuit without load HINT: If a battery/generator tester is available, connect the tester to the charging circuit as per manufacturer's instructions. If a tester is not available, connect a voltmeter and ammeter to the charging circuit as follows: Disconnect the wire from terminals B of the generator and connect it to the negative (-) probe of the ammeter. Connect the positive (+) probe of the ammeter to terminal B of the alternator. Connect the positive (+) probe of the voltmeter to terminal B of the generator Ground the negative (-) probe of the voltmeter Check the charging circuit as follows: With the engine running from idling to 2,000 rpm, check the reading on the ammeter and voltmeter Standard amperage: 10 A or less Standard voltage: 13.6 - 14.8 V at 25° C (77° F) 13.2 - 14.0 V at 115° C (239° F) If the voltmeter reading is greater than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the voltage regulator and generator as follows Remove the engine under cover. With terminal F grounded, start the engine and check the voltmeter reading of terminal B. If the voltmeter reading is greater than standard voltage, replace the voltage regulator. Reinstall the engine under cover.
8. Inspect charging circuit with load With the engine running at 2,000 rpm, turn on the high beam headlights and place the heater blower switch at "HI". Check the reading on the ammeter Standard amperage: 30 a or more If the ammeter reading is less than standard amperage, repair the generator. HINT: With the battery fully charged, the indication will sometimes be less than standard amperage
9. Reinstall engine under cover

Scheme 38

1. Check the electrolyte quantity of each cell. Maintenance-Free Battery: If under the lower level, replace the battery (or add distilled water if possible). Check the charging system. Except Maintenance-Free Battery: If under the lower level, add distilled water.
2. Except Maintenance-Free Battery: Check battery specific gravity Check the specific gravity of each cell. Standard specific gravity: 1.25-1.29 at 20° C (68° F) If the specific gravity is less than specification, charge the battery.
3. Maintenance-Free Battery: Check battery specific gravity After having drive the vehicle and in the case that 20 minutes have not passed after having stopped the engine, turn the ignition switch ON and turn on the electrical system (headlight, blower motor, rear defogger etc.) for 60 seconds to remove the surface charge. Turn the ignition switch OFF and turn off the electrical systems. Measure the battery voltage between the negative (-) and positive (+) terminals of the battery. Standard voltage: 12.5-12.9 V at 20° C (68° F) If the voltage is less than specification, charge the battery. HINT: Check the indicator as shown in the illustration.
4. Check battery terminals, fusible link and fuses Check that the battery terminals are not loose or corroded. If the terminals are corroded, clean the terminals. Check the fusible link and fuses for continuity.
5. Inspect drive belt HINT: A belt tensioner is used, so checking the belt tension is not necessary Visually check the drive belt for excessive wear, frayed cords, etc. If necessary, replace the drive belt. HINT: Cracks on rib side of a drive belt are considered acceptable. If the drive belt has chunks missing from the ribs, it should be replaced. The drive belt tension can be released by turning the belt tensioner clockwise. Check the belt tension operation. Check that the belt tensioner moves downward when the drive belt is pressed down at the points indicated in the illustration with approx. 98 N (10 kgf, 22.0 lbf) of force. Check the alignment of the belt tensioner pulley to make sure the drive belt has not slipped off the pulley. If necessary, replace the belt tensioner. Check that the arrow mark on the belt tensioner falls within area A of the scale. If it is outside area A, replace the drive belt. HINT: When a new belt is installed, it should be within area B. If not, the drive belt is not installed correctly. After installing a belt, check that it fits properly in the ribbed grooves. Check by hand to confirm that the belt has not slipped out of the groove on the bottom of the pulley.
6. Remove engine under cover
7. Visually check generator wiring and listen for abnormal noises Check that the wiring is in good condition. Check that there is no abnormal noise from the generator while the engine is running.
8. Check charge warning light circuit Warm up the engine and then turn it off. Turn off all accessories. Turn the ignition switch ON. Check that the charge warning light is lit. Start the engine. Check that the light goes off If the light does not go off as specified, troubleshoot the charge light circuit.
9. Inspect charging circuit without load HINT: If a battery/generator tester is available, connect the tester to the charging circuit as per manufacturer's instructions. If a tester is not available, connect a voltmeter and ammeter to the charging circuit as follows: Disconnect the wire from terminals B of the generator and connect it to the negative (-) probe of the ammeter. Connect the positive (+) probe of the ammeter to terminal B of the alternator. Connect the positive (+) probe of the voltmeter to terminal B of the generator Ground the negative (-) probe of the voltmeter Check the charging circuit as follows: With the engine running from idling to 2,000 rpm, check the reading on the ammeter and voltmeter Standard amperage: 10 A or less Standard voltage: 13.2 - 14.8 V If the voltmeter reading is greater than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the voltage regulator and generator as follows With terminal F grounded, start the engine and check the voltmeter reading of terminal B. If the voltmeter reading is greater than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the generator
10. Inspect charging circuit with load With the engine running at 2,000 rpm, turn on the high beam headlights and place the heater blower switch at "HI". Check the reading on the ammeter Standard amperage: 30 a or more If the ammeter reading is less than standard amperage, repair the generator. HINT: With the battery fully charged, the indication will sometimes be less than standard amperage
11. Reinstall engine under cover

M.Y. 1995

1. Remove battery clamp cover
2. Check battery electrolyte level and voltage Check the electrolyte quantity of each cell. If under the lower level, replace the battery (or add distilled water if possible). Check the charging system. Measure the battery voltage between the negative (-) and the positive (+) terminals of the battery. Standard voltage: At 20° C (68° F): 12.2 - 12.9 V HINT: Before measuring the voltage, turn the ignition switch OFF and turn off the electrical systems (headlight, blower motor, rear defogger etc.) to remove the surface charge. If the vehicle has been running, wait 20 minutes or more after the vehicle stops before measuring the battery voltage.
3. Check battery terminals and fuses Check that the battery terminals are not loose or corroded. Remove the No. 2 J/B upper cover assembly. Check the fuses for continuity. H-Fuse: ALT 120A AM1 40A AM2 30A Fuse: ENG 7.5A IGN 10a Reinstall the no. 2 J/B upper cover assembly.
4. Inspect drive belt HINT: A belt tensioner is used, so checking the belt tension is not necessary. Visually check the drive belt for excessive wear, frayed cords etc. If necessary, replace the drive belt. HINT: Cracks on the rib side of a drive belt are considered acceptable. If the drive belt has chunks missing from the ribs, it should be replaced. The drive belt tension can be released by turning the belt tensioner counterclockwise. The pulley bolt for the belt tensioner has a left-hand thread. Check the belt tensioner operation. Check that the belt tensioner moves downward when the drive belt is pressed down at the points indicated in the illustration with approx. 98 N (10 kgf, 22 lb.ft) of force. Check that the arrow mark on the belt tensioner falls within area A of the scale If it is outside area A, replace the drive belt HINT: When a new belt is installed, it should lie within area B. If not, the drive belt is not correct. After installing a belt, check that it fits properly in the ribbed grooves. Check by hand to confirm that the belt has not slipped out of the groove on the bottom of the pulley.
5. Remove oil pan protector
6. Remove engine under cover
7. Visually check generator wiring and listen for abnormal noises Check that the wiring is in good condition. Check that there is no abnormal noise from the generator while the engine is running.
8. Check charge warning light circuit warm up the engine and then turn it off. turn off all accessories. Turn the ignition switch "ON". Check that the charge warning light is lit. Start the engine. Check that the light goes off. If the light does not go off as specified, troubleshoot the charge light circuit.
9. Inspect charging circuit without load HINT: If a battery/generator tester is available, connect the tester to the charging circuit as per manufacturer's instructions. If a tester is not available, connect a voltmeter and ammeter to the charging circuit as follows: Disconnect the wire from terminal B of the generator and connect it to the negative (-) probe of the ammeter. Connect the positive (+) probe of the ammeter to terminal B of the generator. Connect the positive (+) probe of the voltmeter to terminal B of the generator. Ground the negative (-) probe of the voltmeter. Check the charging circuit as follows: With the engine running from idling to 2,000 rpm, check the reading on the ammeter and voltmeter. Standard amperage: 10 A or less Standard voltage: At 25° C (77° F): 13.7 - 14.7 V At 115° C (239° F): 13.2 - 14.0 V If the voltmeter reading is more than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the voltage regulator and generator as follows: With terminal F grounded, start the engine and check the voltmeter reading of terminal B. If the voltmeter reading is more than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the generator.
10. Inspect charging circuit with load With the engine running at 2,000 rpm, turn on the high beam headlights and place the heater blower switch at "HI". Check the reading on the ammeter. Standard amperage: 30 A or more If the ammeter reading is less than the standard amperage, repair the alternator. HINT: If the battery is fully charged, the indication will sometimes be less than standard amperage.
11. Reinstall engine under cover
12. Reinstall oil pan protector
13. Reinstall air cleaner inlet
14. Reinstall battery clamp cover

Scheme 39

Scheme 40

Scheme 41

Scheme 42

1. Remove battery clamp cover
2. Check battery electrolyte level check the electrolyte quantity of each cell. If under the lower level, replace the battery (or add distilled water if possible), and check the charging system.
3. Check battery voltage Measure the battery voltage between the negative (-) and the positive (+) terminals of the battery. Standard voltage: 12.2 - 12.9 V at 20° C (68° F) HINT: Before measuring the voltage, turn the ignition switch OFF and turn off the electrical systems (headlight, blower motor, rear defogger etc.) to remove the surface charge. If the vehicle has been running, wait 20 minutes or more after the vehicle stops before measuring the battery voltage. If the voltage is less than specification, charge the battery.
4. Check battery terminals and fuses Check that the battery terminals are not loose or corroded. Check the fuses for continuity.
5. Remove air cleaner inlet
6. Inspect drive belt HINT: A belt tensioner is used, so checking the belt tension is not necessary. Visually check the drive belt for excessive wear, frayed cords etc. If necessary, replace the drive belt. HINT: Cracks on the rib side of a drive belt are considered acceptable. If the drive belt has chunks missing from the ribs, it should be replaced. The drive belt tension can be released by turning the belt tensioner counterclockwise. The pulley bolt for the belt tensioner has a left-hand thread. Check the belt tensioner operation. Check that the belt tensioner moves downward when the drive belt is pressed down at the points indicated in the illustration with approx. 98 N (10 kgf, 22 lb.ft) of force. Check the alignment of the belt tensioner pulley to make sure the drive belt has not slipped off the pulley. If necessary, replace the belt tensioner. Check that the arrow mark on the belt tensioner falls within area A of the scale If it is outside area A, replace the drive belt HINT: When a new belt is installed, it should lie within area B. If not, the drive belt is not correct. After installing a belt, check that it fits properly in the ribbed grooves. Check by hand to confirm that the belt has not slipped out of the groove on the bottom of the pulley.
7. Remove oil pan protector
8. Remove engine under cover
9. Visually check generator wiring and listen for abnormal noises Check that the wiring is in good condition. Check that there is no abnormal noise from the generator while the engine is running.
10. Check charge warning light circuit warm up the engine and then turn it off. turn off all accessories. Turn the ignition switch "ON". Check that the charge warning light is lit. Start the engine. Check that the light goes off. If the light does not go off as specified, troubleshoot the charge light circuit.
11. Inspect charging circuit without load HINT: If a battery/generator tester is available, connect the tester to the charging circuit as per manufacturer's instructions. If a tester is not available, connect a voltmeter and ammeter to the charging circuit as follows: Disconnect the wire from terminal B of the generator and connect it to the negative (-) probe of the ammeter. Connect the positive (+) probe of the ammeter to terminal B of the generator. Connect the positive (+) probe of the voltmeter to terminal B of the generator. Ground the negative (-) probe of the voltmeter. Check the charging circuit as follows: With the engine running from idling to 2,000 rpm, check the reading on the ammeter and voltmeter. Standard amperage: 10 A or less Standard voltage: At 25° C (77° F): 13.7 - 14.7 V At 115° C (239° F): 13.2 - 14.0 V If the voltmeter reading is more than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the voltage regulator and generator as follows: With terminal F grounded, start the engine and check the voltmeter reading of terminal B. If the voltmeter reading is more than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the generator.
12. Inspect charging circuit with load With the engine running at 2,000 rpm, turn on the high beam headlights and place the heater blower switch at "HI". Check the reading on the ammeter. Standard amperage: 30 A or more If the ammeter reading is less than the standard amperage, repair the alternator. HINT: If the battery is fully charged, the indication will sometimes be less than standard amperage.
13. Reinstall engine under cover
14. Reinstall oil pan protector
15. Reinstall air cleaner inlet
16. Reinstall battery clamp cover

Scheme 43

Scheme 44

Scheme 45

Scheme 46

Scheme 47

1. Check battery electrolyte level and voltage Check the electrolyte quantity of each cell. If under the lower level, replace the battery (or add distilled water if possible). Check the charging system Measure the battery voltage between the terminals negative (-) and positive (+) of the battery. Standard voltage: SC300: 12.5 - 12.7 V at 20° C (68° F) HINT: Before measuring the voltage, turn the ignition switch to LOCK and turn off the electrical systems (headlight, blower motor, rear defogger etc.) for 60 seconds to remove the surface charge. If the vehicle has been running, wait 5 minutes or more after the vehicle stops before measuring the battery voltage. If the voltage is less than specification, charge the battery. HINT: Check the indicator as shown in the illustration.
2. Check battery terminals and fuses Check that the battery terminals are not loose or corroded. Check the fusible links and fuses for continuity H-fuse: AlT 120A AM1 100A AM2 30A M-Fuse: IG SW 40A Fuse: INJ 30A IGN 7.5A ENGINE 7.5A
3. Inspect drive belt HINT: A belt tensioner is used, so checking the belt tension is not necessary Visually check the drive belt for excessive wear, frayed cords, etc. If necessary, replace the drive belt. HINT: Cracks on rib side of a drive belt are considered acceptable. If the drive belt has chunks missing from the ribs, it should be replaced. The drive belt tension can be released by turning the belt tensioner clockwise. Check the belt tension operation. Check that the belt tensioner moves downward when the drive belt is pressed down at the points indicated in the illustration with approx. 98 N (10 kgf, 22.0 lbf) of force. Check the alignment of the belt tensioner pulley to make sure the drive belt has not slipped off the pulley. If necessary, replace the belt tensioner. Check that the arrow mark on the belt tensioner falls within area A of the scale. If it is outside area A, replace the drive belt. HINT: When a new belt is installed, it should be within area B. If not, the drive belt is not installed correctly. After installing a belt, check that it fits properly in the ribbed grooves. Check by hand to confirm that the belt has not slipped out of the groove on the bottom of the pulley.
4. Remove engine under cover
5. Visually check generator wiring and listen for abnormal noises Check that the wiring is in good condition. Check that there is no abnormal noise from the generator while the engine is running.
6. Check charge warning light circuit Warm up the engine and then turn it off. Turn off all accessories. Turn the ignition switch ON. Check that the charge warning light is lit. Start the engine. Check that the light goes off If the light does not go off as specified, troubleshoot the charge light circuit.
7. Inspect charging circuit without load HINT: If a battery/generator tester is available, connect the tester to the charging circuit as per manufacturer's instructions. If a tester is not available, connect a voltmeter and ammeter to the charging circuit as follows: Disconnect the wire from terminals B of the generator and connect it to the negative (-) probe of the ammeter. Connect the positive (+) probe of the ammeter to terminal B of the alternator. Connect the positive (+) probe of the voltmeter to terminal B of the generator Ground the negative (-) probe of the voltmeter Check the charging circuit as follows: With the engine running from idling to 2,000 rpm, check the reading on the ammeter and voltmeter Standard amperage: 10 A or less Standard voltage: 13.6 - 14.8 V at 25° C (77° F) 13.2 - 14.0 V at 115° C (239° F) If the voltmeter reading is greater than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the voltage regulator and generator as follows Remove the engine under cover. With terminal F grounded, start the engine and check the voltmeter reading of terminal B. If the voltmeter reading is greater than standard voltage, replace the voltage regulator. Reinstall the engine under cover.
8. Inspect charging circuit with load With the engine running at 2,000 rpm, turn on the high beam headlights and place the heater blower switch at "HI". Check the reading on the ammeter Standard amperage: 30 a or more If the ammeter reading is less than standard amperage, repair the generator. HINT: With the battery fully charged, the indication will sometimes be less than standard amperage
9. Reinstall engine under cover

1. Check the electrolyte quantity of each cell. Maintenance-Free Battery: If under the lower level, replace the battery (or add distilled water if possible). Check the charging system. Except Maintenance-Free Battery: If under the lower level, add distilled water.
2. Except Maintenance-Free Battery: Check battery specific gravity Check the specific gravity of each cell. Standard specific gravity: 1.25-1.29 at 20° C (68° F) If the specific gravity is less than specification, charge the battery.
3. Maintenance-Free Battery: Check battery specific gravity After having drive the vehicle and in the case that 20 minutes have not passed after having stopped the engine, turn the ignition switch ON and turn on the electrical system (headlight, blower motor, rear defogger etc.) for 60 seconds to remove the surface charge. Turn the ignition switch OFF and turn off the electrical systems. Measure the battery voltage between the negative (-) and positive (+) terminals of the battery. Standard voltage: 12.5-12.9 V at 20° C (68° F) IF the voltage is less than specification, charge the battery.
4. Check battery terminals, fusible link and fuses Check that the battery terminals are not loose or corroded. If the terminals are corroded, clean the terminals. Check the fuses for continuity.
5. Inspect drive belts HINT: A belt tensioner is used, so checking the belt tension is not neccessary. Visually check the drive belt for excessive wear, frayed cords etc. If necessary, replace the drive belt. HINT: Cracks on the rib side of a drive belt are considered acceptable. If the drive belt has chunks missing from the ribs, it should be replaced. The drive belt tension can be released by turning the belt tensioner clockwise Check the belt tensioner operation. Check that the belt tensioner moves downward when the drive belt is pressed down at the points indicated in the illustration with approx. 98 N (10 kgf, 22 lb.ft) of force. Check the alignment of the belt tensioner pulley to make sure the drive belt has not slipped off the pulley. If necessary, replace the belt tensioner. Check that the arrow mark on the belt tensioner falls within area A of the scale If it is outside area A, replace the drive belt HINT: When a new belt is installed, it should lie within area B. If not, the drive belt is not correct. After installing a belt, check that it fits properly in the ribbed grooves. Check by hand to confirm that the belt has not slipped out of the groove on the bottom of the pulley.
6. Remove engine under cover
7. Visually check generator wiring and listen for abnormal noises Check that the wiring is in good condition. Check that there is no abnormal noise from the generator while the engine is running.
8. Check charge warning light circuit Warm up the engine and then turn it off. Turn off all accessories. Turn the ignition switch "ON". Check that the charge warning light is lit. Start the engine. Check that the light goes off. If the light does not go off as specified, troubleshoot the charge light circuit.
9. Inspect charging circuit without load HINT: If a battery/generator tester is available, connect the tester to the charging circuit as per manufacturer's instructions. If a tester is not available, connect a voltmeter and ammeter to the charging circuit as follows: Disconnect the wire from terminal B of the generator and connect it to the negative (-) probe of the ammeter. Connect the positive (+) probe of the ammeter to terminal B of the generator. Connect the positive (+) probe of the voltmeter to terminal B of the generator. Ground the negative (-) probe of the voltmeter. Check the charging circuit as follows: With the engine running from idling to 2,000 rpm, check the reading on the ammeter and voltmeter. Standard amperage: 10 A or less Standard voltage: At 25° C (77° F): 13.6 - 14.8 V At 115° C (239° F): 13.2 - 14.0 V If the voltmeter reading is more than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the voltage regulator and generator as follows: With terminal F grounded, start the engine and check the voltmeter reading of terminal B. If the voltmeter reading is more than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the generator.
10. Inspect charging circuit with load With the engine running at 2,000 rpm, turn on the high beam headlights and place the heater blower switch at "HI". Check the reading on the ammeter. Standard amperage: 30 A or more If the ammeter reading is less than the standard amperage, repair the alternator. HINT: If the battery is fully charged, the indication will sometimes be less than standard amperage.
11. Reinstall engine under cover

Scheme 48

Scheme 49

Scheme 50

Scheme 51

Scheme 52

1. Check battery electrolyte level and voltage Check the electrolyte quantity of each cell. If under the lower level, replace the battery (or add distilled water if possible). Check the charging system Measure the battery voltage between the terminals negative (-) and positive (+) of the battery. Standard voltage: SC300: 12.7 - 12.9 V at 20° C (68° F) HINT: Before measuring the voltage, turn the ignition switch to LOCK and turn off the electrical systems (headlight, blower motor, rear defogger etc.) for 60 seconds to remove the surface charge. If the vehicle has been running, wait 5 minutes or more after the vehicle stops before measuring the battery voltage. If the voltage is less than specification, charge the battery. HINT: Check the indicator as shown in the illustration.
2. Check battery terminals and fuses Check that the battery terminals are not loose or corroded. If the terminals are corroded, clean the terminals. Check the fusible links and fuses for continuity H-fuse: AlT 120A AM1 100A AM2 30A M-Fuse: IG SW 40A Fuse: IGN 7.5A ENGINE 7.5A
3. Inspect drive belt HINT: A belt tensioner is used, so checking the belt tension is not necessary Visually check the drive belt for excessive wear, frayed cords, etc. If necessary, replace the drive belt. HINT: Cracks on rib side of a drive belt are considered acceptable. If the drive belt has chunks missing from the ribs, it should be replaced. The drive belt tension can be released by turning the belt tensioner clockwise. Check the belt tension operation. Check that the belt tensioner moves downward when the drive belt is pressed down at the points indicated in the illustration with approx. 98 N (10 kgf, 22.0 lbf) of force. Check the alignment of the belt tensioner pulley to make sure the drive belt has not slipped off the pulley. If necessary, replace the belt tensioner. Check that the arrow mark on the belt tensioner falls within area A of the scale. If it is outside area A, replace the drive belt. HINT: When a new belt is installed, it should be within area B. If not, the drive belt is not installed correctly. After installing a belt, check that it fits properly in the ribbed grooves. Check by hand to confirm that the belt has not slipped out of the groove on the bottom of the pulley.
4. Remove engine under cover
5. Visually check generator wiring and listen for abnormal noises Check that the wiring is in good condition. Check that there is no abnormal noise from the generator while the engine is running.
6. Check charge warning light circuit Warm up the engine and then turn it off. Turn off all accessories. Turn the ignition switch ON. Check that the charge warning light is lit. Start the engine. Check that the light goes off If the light does not go off as specified, troubleshoot the charge light circuit.
7. Inspect charging circuit without load HINT: If a battery/generator tester is available, connect the tester to the charging circuit as per manufacturer's instructions. If a tester is not available, connect a voltmeter and ammeter to the charging circuit as follows: Disconnect the wire from terminals B of the generator and connect it to the negative (-) probe of the ammeter. Connect the positive (+) probe of the ammeter to terminal B of the alternator. Connect the positive (+) probe of the voltmeter to terminal B of the generator Ground the negative (-) probe of the voltmeter Check the charging circuit as follows: With the engine running from idling to 2,000 rpm, check the reading on the ammeter and voltmeter Standard amperage: 10 A or less Standard voltage: 13.6 - 14.8 V at 25° C (77° F) 13.2 - 14.0 V at 115° C (239° F) If the voltmeter reading is greater than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the voltage regulator and generator as follows Remove the engine under cover. With terminal F grounded, start the engine and check the voltmeter reading of terminal B. If the voltmeter reading is more than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the generator.
8. Inspect charging circuit with load With the engine running at 2,000 rpm, turn on the high beam headlights and place the heater blower switch at "HI". Check the reading on the ammeter Standard amperage: 30 a or more If the ammeter reading is less than standard amperage, repair the generator. HINT: With the battery fully charged, the indication will sometimes be less than standard amperage
9. Reinstall engine under cover

1. Check battery electrolyte level Check the electrolyte quantity of each cell. Maintenance-Free Battery; If under the lower level, replace the battery (or add distilled water if possible). Check the charging system. Except Maintenance-Free Battery: If under the lower level, add distilled water.
2. Remove battery clamp cover
3. Except Maintenance-Free Battery: Check battery specific gravity Check the specific gravity of each cell. Standard specific gravity: 1.25-1.29 at 20° C (68° F) If the specific gravity is less than specification, charge the battery.
4. Maintenance-Free Battery: Check battery specific gravity After having drive the vehicle and in the case that 20 minutes have not passed after having stopped the engine, turn the ignition switch ON and turn on the electrical system (headlight, blower motor, rear defogger etc.) for 60 seconds to remove the surface charge. Turn the ignition switch OFF and turn off the electrical systems. Measure the battery voltage between the negative (-) and positive (+) terminals of the battery. Standard voltage: 12.5-12.9 V at 20° C (68° F) If the voltage is less than specification, charge the battery.
5. Check battery terminals, fusible link and fuses Check that the battery terminals are not loose or corroded. If the terminals are corroded, clean the terminals. Check the fusible link, H-fuse, M-fuse and fuses for continuity.
6. Inspect drive belt HINT: A belt tensioner is used, so checking the belt tension is not necessary. Visually check the drive belt for excessive wear, frayed cords, etc. If necessary, replace the drive belt. HINT: Cracks on the rib side of a drive belt are considered acceptable. If the drive belt has chunks missing from the ribs, it should be replaced. The drive belt tension can be released by turning the belt tensioner clockwise. Check the belt tensioner operation. Check that the belt tensioner moves downward when the drive belt is pressed down at the points indicated in the illustration with approx. 98 N (10 kgf, 22.0 lbf) of force. Check the alignment of the belt tensioner pulley to make sure the drive belt has not slipped off the pulley. If necessary, replace the belt tensioner. Check that the arrow mark on the belt tensioner falls within area A of the scale. If it is outside area A, replace the drive belt. HINT: When a new belt is installed, it should be within area B. If not, the drive belt is not installed correctly. After installing a belt, check that it fits properly in the ribbed grooves. Check by hand to confirm that the belt has not slipped out of the groove on the bottom of the pulley.
7. Remove engine under
8. Visually check generator wiring and listen for abnormal noises Check that the wiring is in good condition. Check that there is no abnormal noise from the generator while the engine is running.
9. Check charge warning light circuit Warm up the engine and then turn it off. Turn off all accessories. Turn the ignition switch "ON". Check that the charge warning light is lit. Start the engine. Check that the light goes off. If the light does not go off as specified, troubleshoot the charge light circuit.
10. Inspect charging circuit without load HINT: If a battery/generator tester is available, connect the tester to the charging circuit as per manufacturer's instructions. If a tester is not available, connect a voltmeter and ammeter to the charging circuit as follows: Disconnect the wire from terminal B of the generator and connect it to the negative (-) probe of the ammeter. Connect the positive (+) probe of the ammeter to terminal B of the generator. Connect the positive (+) probe of the voltmeter to terminal B of the generator. Ground the negative (-) probe of the voltmeter. Check the charging circuit as follows: With the engine running from idling to 2,000 rpm, check the reading on the ammeter and voltmeter. Standard amperage: 10 A or less Standard voltage: At 25° C (77° F): 13.7 - 14.7 V At 115° C (239° F): 13.2 - 14.0 V If the voltmeter reading is more than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the voltage regulator and generator as follows: With terminal F grounded, start the engine and check the voltmeter reading of terminal B. If the voltmeter reading is more than standard voltage, replace the voltage regulator. If the voltmeter reading is less than standard voltage, check the generator.
11. Inspect charging circuit with load With the engine running at 2,000 rpm, turn on the high beam headlights and place the heater blower switch at "HI". Check the reading on the ammeter. Standard amperage: 30 A or more If the ammeter reading is less than the standard amperage, repair the alternator. HINT: If the battery is fully charged, the indication will sometimes be less than standard amperage.
12. Reinstall engine under cover
13. Reinstall battery clamp cover

GENERATOR OUTPUT

1. Connect charging system test equipment as described in manufacturer's instructions. Check charging system output voltage at 2000 RPM. If output voltage is high, replace voltage regulator and retest. If output voltage is low, go to next step. If output voltage is correct, go to step 3). See «GENERATOR OUTPUT SPECIFICATIONS»(ref-60541-S11404708552001011800000) table.
2. If output voltage is low, by-pass regulator (full field generator) by grounding terminal "F" at back of generator. (Scheme 54), (Scheme 55) or see scheme 102. Recheck charging system output voltage. If voltage now exceeds output voltage specified in «GENERATOR OUTPUT SPECIFICATIONS»(ref-60541-S11404708552001011800000) table, replace regulator and recheck. If output voltage is still incorrect, repair or replace generator.
3. With engine at 2000 RPM, place the heater blower switch on highest setting and turn on headlights (high beam). Ammeter reading should be 30 amps or more. If amperage output is incorrect, repair or replace generator.

GENERATOR OUTPUT SPECIFICATIONS (@ 2000 RPM) (1)

Scheme 53

Scheme 54

Scheme 55

BRUSHES

Check brushes for cracks and a minimum exposed length of .059" (1.5 mm). Replace brushes if damaged or worn. Brushes should slide freely in holders. Install NEW springs when replacing brushes. Solder brush wire into place.

ROTOR

1. Check rotor for open field windings by measuring resistance across slip rings. Rotor resistance should be within rotor specifications. See «ROTOR RESISTANCE SPECIFICATIONS»(ref-60541-S16946692632001011800000) table. Check rotor for short circuit to ground by connecting ohmmeter between one slip ring and rotor shaft. Continuity should not exist.
2. Check slip rings for wear or damage. Turn rotor/slip rings on lathe if necessary. Ensure slip ring diameter is not less than .504" (12.8 mm). Check bearing and replace if necessary.

ROTOR RESISTANCE SPECIFICATIONS

STATOR

Using ohmmeter, check continuity between stator leads. Continuity should exist between all stator leads. Check continuity between stator lead and generator housing. Continuity should not exist. Replace stator if continuity is not as specified.