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Charging System - Generators & Regulators: Diagnosis Mercury Sable IV

Charging System 2 illustrations ~2404 words

TROUBLE SHOOTING

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

BATTERY DRAIN TEST

Note. Amperage draw will vary from vehicle to vehicle depending on equipment package. Compare to a comparable vehicle for reference. No production vehicle should have more than a 50 mA (0.050 amp) draw.

  1. Ensure junction box/fuse panels are accessible without turning on interior and hood lights. Drive vehicle over 30 MPH for at least 5 minutes. Park vehicle and allow to sit with ignition off for at least 40 minutes to allow electronic modules to power down. Go to next step.
  2. Connect a fused jumper wire between negative battery cable and negative battery post. Disconnect negative battery cable from negative battery post, without breaking the jumper wire connection to prevent modules from resetting. Go to next step. NOTE: It is very important that continuity is not broken between negative battery post and negative battery cable when disconnecting battery cable or connecting ammeter. If continuity is broken, go to step 1 .
  3. Ensure ammeter is set to read milliamps with at least a 10 amp capability. Connect ammeter between negative battery cable and negative battery post. Remove fused jumper wire. Go to next step.
  4. If excessive current draw is present (50 mA or more), pull fuses from battery/central junction box one at a time and note any current drop when each fuse is removed. DO NOT reinstall fuses until test is complete. Go to next step.
  5. Check wiring diagrams for any circuits that run from battery without passing through battery/central junction box. Disconnect these circuits if current draw still exists. Repair appropriate circuits as necessary. See POWER DISTRIBUTION in appropriate SYSTEM WIRING DIAGRAMS article.

BATTERY DRAINS THAT SHUT OFF WHEN BATTERY CABLE IS DISCONNECTED TEST

  1. Perform battery drain test. See «BATTERY DRAIN TEST»(ref-139460-S28239143362002050100000) . Ensure all doors are closed and accessories are off. Without starting engine, turn ignition switch to RUN position for a moment, and then turn ignition OFF. Wait a few minutes for illuminated entry lamps to turn off (if equipped).
  2. Connect ammeter between negative battery cable and negative battery post. Disconnect negative battery cable from negative battery post, without breaking the ammeter connection to prevent modules from resetting. Read amperage draw.
  3. Amperage draw should be less than 50 milliamps. If current draw exceeds 50 milliamps, remove fuses from battery/central junction box one at a time to locate problem circuit.

GENERATOR LOAD TEST

Ensure drive belt is in good condition. Replace belt as necessary. If belt is okay, connect charging system load tester in accordance with manufacturer's instructions. Start and run engine at 2000 RPM, and apply load until generator output levels off. Generator amperage should be at least 87 amps with engine at 2000 RPM. Go to next step. If output is not as specified, see SYMPTOM INDEX table under SYSTEM TESTS.

GENERATOR NO-LOAD TEST

  1. Connect voltmeter positive lead to B+ terminal on generator and negative lead to ground. Start and run engine at 2000 RPM with no electrical load (all accessories off). Read voltmeter when voltage stabilizes. Voltage should be 13-15 volts. If voltage is not as specified, see «SYMPTOM INDEX»(ref-139460-S33678563402002050100000) table under SYSTEM TESTS.
  2. Turn A/C on, blower motor on high speed and headlamps on high beam. Voltage should be within 0.5 volt of previously measured voltage. If voltage does not increase as specified, see «SYMPTOM INDEX»(ref-139460-S33678563402002050100000) table under SYSTEM TESTS. If the voltage is as specified, charging system is operating normally.

SELF-DIAGNOSTIC SYSTEM

Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Using NGS tester, perform Powertrain Control Module (PCM) self-test. If any DTCs exist, perform appropriate test in accordance with DTC retrieved. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE. If no DTCs are present, repair by symptom. See SYMPTOM INDEX table under SYSTEM TESTS.

TEST A: BATTERY IS DISCHARGED OR VOLTAGE IS LOW

  1. Perform generator load and no-load tests. See «GENERATOR LOAD TEST»(ref-139460-S29051466462002050100000) and «GENERATOR NO-LOAD TEST»(ref-139460-S36685546442002050100000) under ON-VEHICLE TESTING. If generator is okay, go to next step. If generator is not okay, perform «TEST B: WARNING INDICATOR ON WITH ENGINE RUNNING, SYSTEM NOT CHARGING»(ref-139460-S13358873242002050100000) .
  2. Perform «BATTERY DRAIN TEST»(ref-139460-S28239143362002050100000) under ON-VEHICLE TESTING. If no excessive current draw was not found, go to next step. If any excessive current draw was found, repair as necessary.
  3. Perform «BATTERY DRAINS THAT SHUT OFF WHEN BATTERY CABLE IS DISCONNECTED TEST»(ref-139460-S04603759572004072800000) under ON-VEHICLE TESTING. If there are any current drains that shut off when the battery is disconnected, repair as necessary. If no drains were found, perform «TEST B: WARNING INDICATOR ON WITH ENGINE RUNNING, SYSTEM NOT CHARGING»(ref-139460-S13358873242002050100000) .

TEST B: WARNING INDICATOR ON WITH ENGINE RUNNING, SYSTEM NOT CHARGING

  1. Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition on. Using NGS tester, perform Powertrain Control Module (PCM) self-test. If no DTCs are retrieved, go to next step. If any Diagnostic Trouble Codes (DTC) are retrieved, perform appropriate test in accordance with DTC retrieved. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
  2. Turn ignition off. Disconnect NGS tester. Disconnect generator 3-pin harness connector. Turn ignition on. Measure voltage between ground and generator harness connector terminal No. 2 (Light Blue/Red wire). (Scheme 1) If voltage is not present, go to next step. If voltage is present, go to step 4.
  3. Turn ignition off. Disconnect PCM harness connector C175. Measure resistance of Light Blue/Red wire between generator harness connector and terminal No. 45 at PCM harness connector C175. (Scheme 2) If resistance is 5 ohms or less, go to next step. If resistance is greater than 5 ohms, repair open in Light Blue/Red wire between generator and PCM.
  4. Connect PCM harness connector C175. Connect generator 3-pin harness connector. Check generator output. Perform «GENERATOR LOAD TEST»(ref-139460-S29051466462002050100000) and «GENERATOR NO-LOAD TEST»(ref-139460-S36685546442002050100000) under ON-VEHICLE TESTING. If generator is okay, go to next step. If generator is not okay, replace generator. See «GENERATOR»(ref-139460-S26240772262002050100000) under REMOVAL & INSTALLATION.
  5. Disconnect PCM harness connector C175. Inspect harness connector for pushed out pins, corrosion or bent terminals. Repair as necessary. If harness connector is okay, reconnect and retest system operation. If fault is still present, replace PCM. Clear DTCs and repeat PCM self-test. If fault is still not present, system is operating correctly at this time.

Scheme 1

Scheme 1
Scheme 1

Scheme 2

Scheme 2
Scheme 2

TEST C: SYSTEM OVERCHARGES (MORE THAN 15 VOLTS)

  1. Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition on. Using NGS tester, perform Powertrain Control Module (PCM) self-test. If no DTCs are retrieved, go to next step. If any Diagnostic Trouble Codes (DTC) are retrieved, perform appropriate test in accordance with DTC retrieved. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
  2. Turn ignition off. Disconnect NGS tester. Start engine. With engine running and all accessories turned off, measure the voltage at battery while varying engine RPM. If the voltage is more than 15 volts, go to next step. If voltage is not more than 15 volts, go to step 4.
  3. Turn ignition off. Disconnect generator 3-pin connector. Turn ignition on. Measure voltage between ground and generator harness connector terminal No. 3 (Orange/Yellow wire). (Scheme 1) If voltage is less than 0.5 volt from battery voltage, go to next step. If voltage is 0.5 volt or more from battery voltage, repair Orange/Yellow wire. See «WIRING DIAGRAMS»(ref-139460-S04080246422002050100000). After repair, clear DTCs and test system for normal operation.
  4. Turn ignition off. Connect generator 3-pin harness connector. Start engine. Check generator output. See «GENERATOR LOAD TEST»(ref-139460-S29051466462002050100000) and «GENERATOR NO-LOAD TEST»(ref-139460-S36685546442002050100000) under ON-VEHICLE TESTING. If generator is okay, system is operating correctly at this time. Check for corroded connections and check integrity of Orange/Yellow wire. If generator is not okay, install new generator. See «GENERATOR»(ref-139460-S26240772262002050100000) under REMOVAL & INSTALLATION. Clear the DTCs. Test the system for normal operation.

TEST D: WARNING INDICATOR ON WITH ENGINE RUNNING, SYSTEM IS CHARGING

  1. Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition on. Using NGS tester, perform Powertrain Control Module (PCM) self-test. If no DTCs are retrieved, go to next step. If any Diagnostic Trouble Codes (DTC) are retrieved, perform appropriate test in accordance with DTC retrieved. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
  2. Turn ignition off. Disconnect NGS tester. Start engine. With engine running and all accessories turned off, measure voltage between battery terminals while varying engine speed. If voltage is less than 15 volts, go to next step. If voltage is greater than 15 volts, perform «TEST C: SYSTEM OVERCHARGES (MORE THAN 15 VOLTS)»(ref-139460-S15248238002002050100000).
  3. Turn ignition off. Disconnect generator 3-pin harness connector. Turn ignition on. Measure voltage between ground and generator harness connector terminal No. 3 (Orange/Yellow wire). (Scheme 1) If battery voltage is present, go to next step. If battery voltage is not present, repair open or short in Orange/Yellow wire. See «WIRING DIAGRAMS»(ref-139460-S04080246422002050100000).
  4. Turn ignition off. Disconnect PCM harness connector C175. Turn ignition on and observe warning indicator. If warning indicator is not illuminated, go to next step. If warning indicator is illuminated, repair short to ground in Light Blue/Red wire between generator and PCM. See «WIRING DIAGRAMS»(ref-139460-S04080246422002050100000).
  5. Turn ignition off. Reconnect PCM harness connector C175. Reconnect generator 3-pin harness connector. Check generator output. See «GENERATOR LOAD TEST»(ref-139460-S29051466462002050100000) and «GENERATOR NO-LOAD TEST»(ref-139460-S36685546442002050100000) under ON-VEHICLE TESTING. If generator tests okay, go to next step. If generator does not test okay, replace generator. See «GENERATOR»(ref-139460-S26240772262002050100000) under REMOVAL & INSTALLATION.
  6. Disconnect PCM harness connector C175. Inspect harness connector for pushed out pins, corrosion or bent terminals. Repair as necessary. If harness connector is okay, reconnect and retest system operation. If fault is still present, replace PCM. Clear DTCs and repeat PCM self-test. If fault is still not present, system is operating correctly at this time.

TEST E: WARNING INDICATOR OFF WITH IGNITION ON

  1. Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition on. Using NGS tester, perform Powertrain Control Module (PCM) self-test. If no DTCs are retrieved, go to next step. If any Diagnostic Trouble Codes (DTC) are retrieved, perform appropriate test in accordance with DTC retrieved. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
  2. Turn ignition off. Disconnect NGS tester and generator 3-pin harness connector. Turn ignition on. Connect a fused (15-amp) jumper wire between generator harness connector terminal No. 2 (Light Blue/Red wire) and ground. If warning indicator does not illuminate, go to next step. If warning indicator illuminates, replace generator. See «GENERATOR»(ref-139460-S26240772262002050100000) under REMOVAL & INSTALLATION.
  3. Turn ignition off. Disconnect PCM connector C175. Measure resistance between PCM connector C175 terminal No. 45 and Light Blue/Red wire terminal at generator connector. (Scheme 2) If the resistance is less than 5 ohms, go to next step. If the resistance is 5 ohms or more, repair open in Light Blue/Red wire. Test the system for normal operation.
  4. Disconnect PCM harness connector C175. Inspect harness connector for pushed out pins, corrosion or bent terminals. Repair as necessary. If harness connector is okay, reconnect and retest system operation. If fault is still present, replace PCM. Clear DTCs and repeat PCM self-test. If fault is still not present, system is operating correctly at this time.

TEST F: CHARGE WARNING INDICATOR FLICKERS OR IS INTERMITTENT

  1. Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition on. Using NGS tester, perform Powertrain Control Module (PCM) self-test. If no DTCs are retrieved, go to next step. If any Diagnostic Trouble Codes (DTC) are retrieved, perform appropriate test in accordance with DTC retrieved. See appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
  2. Inspect battery, Battery Junction Box (BJB), Central Junction Box (CJB) and generator connectors for loose, corroded or damaged connections. Repair as necessary and retest system operation. If all connections are okay, go to next step.
  3. Start engine. Wiggle fuse No. 26 (10-amp) in BJB while observing charge warning indicator. If charge warning indicator does not flicker, go to next step. If charge warning indicator flickers, repair appropriate loose connection and retest system operation.
  4. With engine running and all accessories turned off, measure voltage between battery terminals. If battery voltage is less than 15 volts, go to next step. If battery voltage is greater than 15 volts, perform «TEST C: SYSTEM OVERCHARGES (MORE THAN 15 VOLTS)»(ref-139460-S15248238002002050100000) .
  5. Turn ignition off. Disconnect generator 3-pin harness connector. Connect a fused (15-amp) jumper wire between generator harness connector terminal No. 2 (Light Blue/Red wire) and ground. Turn ignition on and observe warning indicator. If warning indicator illuminates, go to next step. If warning indicator does not illuminate, go to step 7 .
  6. Turn ignition off. Reconnect generator 3-pin connector. Turn ignition on. Monitor the charging system warning indicator operation. If charging system warning indicator is illuminated, PCM is operating correctly. Recheck the generator circuits (including the generator) for intermittent shorts or opens. Test the system for normal operation. If charging system warning indicator is not illuminated, install a new generator. See «GENERATOR»(ref-139460-S26240772262002050100000) under REMOVAL & INSTALLATION. Clear DTCs and TEST system for normal operation.
  7. Turn ignition off. Disconnect PCM connector C175. Measure resistance between the PCM connector C175 terminal No. 45 and Light Blue wire terminal in generator connector. If resistance less than 5 ohms, go to next step. If resistance is 5 ohms or more, repair open in Light Blue/Red wire. Test system for normal operation.
  8. Disconnect PCM harness connector C175. Inspect harness connector for pushed out pins, corrosion or bent terminals. Repair as necessary. If harness connector is okay, reconnect and retest system operation. If fault is still present, replace PCM. Clear DTCs and repeat PCM self-test. If fault is still not present, system is operating correctly at this time.

TEST G: GENERATOR NOISY

  1. Turn ignition off. Check accessory drive belt for damage and correct installation. Check mounting brackets and pulleys for looseness and damage. If problem does not exist, go to next step. If problem exists, repair as necessary.
  2. Disconnect generator 3-pin harness connector. Start engine and let idle. If noise still exists, go to next step. If noise does not still exist, replace generator.
  3. Turn ignition off. Connect generator harness connector. Start engine and let idle. Turn all accessories off. Using a stethoscope, check generator for unusual mechanical noise. If generator is source of noise, replace generator. If generator is not source of noise, isolate noise and repair as necessary.

TEST H: RADIO INTERFERENCE

Start engine and let idle. Tune radio to station where interference is present. Turn ignition off. Disconnect generator 3-pin harness connector. Start engine and let idle. If interference is still present, repair radio concern. If interference is not still present, replace generator.

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