Charging System: Diagnosis Chevrolet Tracker II

Circuit Description

The generator provides voltage to operate the vehicle's electrical system and to charge its battery. A magnetic field is created when current flows through the rotor. This field rotates as the rotor is driven by the engine, creating an AC voltage in the stator windings. The AC voltage is converted to DC by the rectifier bridge and is supplied to the electrical system at the battery terminal.

When the engine is running, and the generator is rotating, a voltage is generated in the stator. The generator's voltage regulator senses this voltage and controls current to the rotor, thereby controlling the output voltage. The rotor current is proportional to the electrical pulse width supplied by the regulator. When the engine is started, the regulator senses generator rotation by detecting AC voltage at the stator through an internal wire. Once the engine is running, the regulator varies the field current by controlling the pulse width. This regulates the generator output voltage for proper battery charging and electrical system operation. The generator F terminal is connected internally to the voltage regulator. When the voltage regulator detects a charging system problem, it grounds this circuit which illuminates the charge indicator lamp. The system voltage sense circuit receives ignition voltage through the IG fuse in the junction block. This voltage is used by the regulator as the reference for system voltage control.

When the ignition switch is turned to ON, the charge indicator turns on for a few seconds (bulb check), then turns off. When the generator is not rotating, the regulator provides a ground which causes the charge indicator to illuminate. When the generator is rotating, the regulator provides a separate output voltage to the charge indicator. Since equal voltage is now provided to both sides of the charge indicator, the lamp loses its ground and goes out.

TROUBLE SHOOTING

Note. See CHARGING SYSTEM - GENERAL TROUBLE SHOOTING article in GENERAL INFORMATION.

DIAGNOSTIC STARTING POINT - ENGINE ELECTRICAL

Begin the system diagnosis by reviewing the following Description and Operations.

1. «DESCRIPTION & OPERATION»(ref-126042-S18847822912001101900000) .
2. «DESCRIPTION»(ref-126046-S38411809082001101900000) and «OPERATION»(ref-126046-S28088939862001101900000) in STARTER article.

Reviewing the Description and Operation information will help you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the Description and Operation information will also help you determine if the condition described by the customer is normal operation. See

SYMPTOMS - ENGINE ELECTRICAL

in order to identify the correct procedure for diagnosing the system and where the procedure is located.

SYMPTOMS - ENGINE ELECTRICAL

Review the system operation in order to familiarize yourself with the system functions. Refer to the following

1. «DESCRIPTION & OPERATION»(ref-126042-S18847822912001101900000) .
2. «DESCRIPTION»(ref-126046-S38411809082001101900000) and «OPERATION»(ref-126046-S28088939862001101900000) in STARTER article.

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the starting, charging or ignition systems.
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
3. Inspect the battery for correct installation and physical damage.
4. Test the condition of the battery. Terminal voltage should be 11.5-13.5 volts.
5. Inspect the wiring for damage. Inspect the connections to the starter motor, the starter solenoid, the ignition switch, the battery and all related ground points.
6. If the battery, wiring and switches are in satisfactory condition and the engine is known to be functioning properly, remove and test the starter motor. See «OVERHAUL»(ref-126046-S27468061612001101900000) in STARTER article in ENGINE.
7. When the charging system is operating normally, the charge indicator lamp will come on when the ignition switch is turned on and will go out when the engine starts.
8. Inspect the generator for loose or improper mounting and the generator drive belt for correct installation.
9. Inspect the generator drive belt for correct installation. See «SPECIFICATIONS & DRIVE BELT ROUTING»(ref-24712) .

Symptom List

For symptoms and testing see, SYSTEM TESTS .

ON-VEHICLE TESTING

Note. Before making electrical checks, visually inspect all terminals for clean, tight connections. Ensure all charging system related fuses are okay. Check generator mounting bolts and drive belt tension. Ensure battery is in good condition prior to testing charging system.

Note. The battery test using the J 42000 Digital Battery Tester requires correct connections to the battery terminals. A failure to obtain the correct connections during the test may result in a failed test on a good battery.

Diagnostic Aids

Note. Required Tools: J 42000 Digital Battery Tester

Follow these instructions in order to avoid an incorrect diagnosis because of connections

1. If testing the vehicle with the battery cables still connected, wiggle the J 42000 clips on the terminal bolt. This may cut through any coating or through any oxidation that may be present on the bolt. Even new bolts contain a protective coating that may insulate or cause a resistance in the test circuit.
2. If correct connections to the battery terminal bolts in the vehicle are in doubt, perform the following steps: Disconnect the negative battery cable. Disconnect the positive battery cable. Install the test adapters on the terminals. Follow the instructions for testing a removed battery.
3. If the tester displays a REPLACE BATTERY result for a battery tested in the vehicle with the battery cables connected, perform the following steps: Disconnect the negative battery cable. Disconnect the positive battery cable. Install the tester adapters. Follow the instructions for testing a removed battery. Replace the battery only if the second test shows a REPLACE BATTERY result. Use the test code from the second test for any warranty purposes.
4. Use the correct terminal adapters. Do not use any common bolts or a combination of bolts, of nuts, and of washers as adapters when testing the battery. Use the test adapters that are provided with the J 42000 or P/N 12303040 terminal adapters. If the adapters that are provided with the J 42000 require replacement, use P/N 12303040. Any other adapter may not contact the correct areas of the battery terminal, causing a resistance that may result in an invalid battery test result.

Testing

1. Inspect the battery for a cracked, broken, or damaged case, which may be indicated by battery acid leakage. Is the battery okay? If so, go to next step. If not, go to step 19 .
2. Compare the Cold Cranking Amperage (CCA) and Reserve Capacity (RC) of the battery to the original battery or Original Equipment (OE) specification. See «BATTERY SPECIFICATIONS»(ref-126042-S32685931012001101900000) table. Does the battery meet or exceed the specifications? If so, go to next step. If not, go to step 19 .
3. Inspect battery hydrometer display. If hydrometer display shows a Yellow dot, go to next step. If hydrometer display does not show a Yellow dot, go to step 5 .
4. Using a small screwdriver, tap top of hydrometer display to dislodge any air bubbles inside. If hydrometer display still shows a Yellow dot, go to step 19 . If hydrometer display does not show a Yellow dot, go to next step.
5. Turn ignition switch OFF. Attempt to rotate negative battery cable connector clockwise with light finger pressure. If negative connector rotates, go to next step. If negative connector does not rotate, go to step 7 .
6. Use a torque wrench in order to verify the torque to loosen the negative battery terminal bolt. Is the torque above the specified value of 89 in. lbs. (10 N.m)? If so, go to step 8 . If not, go to next step.
7. Disconnect negative battery cable and go to step 9 .
8. Disconnect the negative battery cable. Inspect that the cable bolt is not too long or deformed at the end. Is there is foreign material present inside the nut in the battery terminal, damage to the battery terminal face or cable connector ring? Repair as needed. After repair is complete, go to next step.
9. Attempt to rotate positive battery cable connector clockwise with light finger pressure. If battery cable rotates, go to next step. If battery cable does not rotate, go to step 11 .
10. Use a torque wrench in order to verify the torque to loosen the positive battery terminal bolt. Is the torque above the specified value of 89 Inch Lbs. (10 N.m)? If so, go to step 12 . If not, go to next step.
11. Disconnect positive battery cable and go to step 13 .
12. Disconnect the negative battery cable. Inspect that the cable bolt is not too long or deformed at the end. Is there is foreign material present inside the nut in the battery terminal, damage to the battery terminal face or cable connector ring? Repair as needed. After repair, go to next step.
13. Clean and wire brush lead face of both battery terminals and metal contact surfaces on both cable connectors. Remove bolts from both battery cable connectors and inspect for corrosion and defects. Repair or replace as necessary. If battery and cables terminals are clean and in good condition, go to next step.
14. Connect positive battery cable to battery and tighten bolt to 11 ft. lbs. (15 N.m). Go to next step.
15. Connect negative battery cable to battery and tighten bolt to 11 ft. lbs. (15 N.m). Go to next step.
16. Ensure all electrical loads are off. Follow manufacturers instructions and install Battery Tester (J-42000) to vehicle battery. Follow any instructions displayed on battery tester. If battery tester passed the battery, go to next step. If battery tester did not pass battery, go to step 18 . NOTE: Always write the test code displayed by the tester on the repair order for any warranty purposes. The number is a unique code that describes the test data for a particular battery at a particular time. The test code may occasionally repeat when you retest the same battery. More often, each test will result in a different code.
17. Press CODE button on battery tester. Record displayed code on vehicle repair order for warranty purposes. Battery is okay.
18. Press CODE button on battery tester. Record displayed code on vehicle repair order for warranty purposes. Replace battery.
19. Replace battery.

BATTERY SPECIFICATIONS

TEST B: CHARGE INDICATOR ALWAYS ON

1. Did you review the DESCRIPTION & OPERATION? If so, go to next step. If not, go to «SYMPTOMS - ENGINE ELECTRICAL»(ref-126042-S01579768892004113000000) under TROUBLE SHOOTING.
2. Start engine. Does the battery charge indicator remain illuminated after the five second bulb check? If so, go to next step. If not, see «INTERMITTENTS»(ref-126042-S06188385562004112900000) in SYMPTOMS - ENGINE ELECTRICAL under TROUBLE SHOOTING.
3. Install a scan tool. With a scan tool, observe the BATTERY VOLTAGE PARAMETER in the POWERTRAIN DATA LIST. Does the voltage measure within the normal operating range of 10-15V? If so, go to next step. If not, see «TEST A: CHARGING SYSTEM TEST»(ref-126042-S07336612312001101900000) .
4. Test the charge indicator ground circuit for a short to ground. Did you find and correct the condition? If so, go to next step.
5. Operate system to verify repair. If condition was found and corrected, system is okay. If condition was not found, go to step 3 .

TEST C: CHARGE INDICATOR LIGHT INOPERATIVE

1. Did you review the DESCRIPTION & OPERATION? If so, go to next step. If not, see «SYMPTOMS - ENGINE ELECTRICAL»(ref-126042-S01579768892004113000000) under TROUBLE SHOOTING.
2. Turn ON the ignition, with the engine OFF. Does the battery charge indicator illuminate for five seconds during bulb check? If so, see «INTERMITTENTS»(ref-126042-S06188385562004112900000) in SYMPTOMS - ENGINE ELECTRICAL under TROUBLE SHOOTING. If not, go to next step.
3. Disconnect the generator connector. Connect a 20 amp fused jumper to the charge indicator ground circuit. Turn the ignition switch to the ON position. Does the battery charge indicator illuminate? If so, go to next step. If not, go to step 6 .
4. Test the generator supply voltage circuit for an open. Did you find and correct the condition? If so, go to step 9 . If not, go to next step.
5. Replace IC regulator. See «OVERHAUL»(ref-126042-S18703229872001101900000) . After repair, go to step 9 .
6. Inspect the charge indicator bulb and replace as necessary. Test the charge indicator supply voltage circuit for an open. Did you find and correct the condition? If so, go to step 9 . If not, go to next step.
7. Test the charge indicator ground circuit for an open. Did you find and correct the condition? If so, go to step 9 . If not, go to next step.
8. Repair or replace instrument cluster printed circuit. After repairs, go to next step.
9. Operate system to verify repair. If condition was found and corrected, system is okay. If condition was not found, go to step 2 .

Noise from a generator may be due to electrical or mechanical noise. Electrical noise (magnetic whine) usually varies with the electrical load placed on the generator and is a normal operating characteristic of all generators. When diagnosing a noisy generator, it is important to remember that loose or misaligned components around the generator may transmit the noise into the passenger compartment and that replacing the generator may not solve the problem.

1. Test generator for proper operation. See «TEST A: CHARGING SYSTEM TEST»(ref-126042-S07336612312001101900000) . Is the generator operating properly? If so, go to next step. If not, go to step 11 .
2. Start engine. Verify that generator noise can be heard. Turn ignition switch to LOCK position. Disconnect generator harness connector. Start engine. Listen for generator noise. If noise has stopped, go to step 11 . If noise is still present, go to next step.
3. Turn engine off. Remove drive belt. Spin generator pulley by hand. If pulley rotates smoothly and no noise is present, go to next step. If pulley rotates roughly and/or noise is present, go to step 11 .
4. Inspect pulley for looseness, or loose pulley nut. If pulley and nut are okay, go to step 11 . If pulley and/or nut is loose, repair as necessary and go to next step.
5. Loosen all generator mounting bolts. Tighten generator mounting bolts to specification. See «TORQUE SPECIFICATIONS»(ref-126042-S10760635262001101900000) . Install drive belt. Start engine and listen for noise. If noise has decreased or stopped, system is okay. If noise is still present, go to next step.
6. Check for stretched generator connections, or hoses or other equipment rubbing on generator. If problem exists, go to next step. If problem does not exist, go to step 8 .
7. Reroute electrical connections, hoses, etc., away from generator. Start engine and listen for noises. If noise has decreased or stopped, system is okay. If noise is still present, go to next step.
8. Check drive belt for proper tension. If drive belt is loose, go to next step. If drive belt is okay, go to step 10 .
9. Replace drive belt tensioner. Start engine and listen for noise. If noise has decreased or stopped, system is okay. If noise is still present, go to step 11 .
10. Check comparable vehicle for similar noise. If noise is present in similar vehicle, system is okay. If noise is not present in similar vehicle, go to next step. NOTE: If no definite generator problems were found, be sure that all other possible sources of objectionable noise are eliminated before replacing the generator. Replacing the generator may not change the noise level if the noise is a normal characteristic of the generator or the generator mounting.
11. Replace generator. See «GENERATOR»(ref-126042-S13747037612001101900000) under REMOVAL & INSTALLATION. Has the noise decreased or stopped? If so, go to next step.
12. Operate the system in order to verify the repair. Did you correct the condition? If so, then system is okay. If not, go to step 2 .