Generators & Regulators: Diagnosis Lincoln LS I

TROUBLE SHOOTING

Note. See TROUBLE SHOOTING article in GENERAL INFORMATION.

GENERATOR LOAD TEST

Verify battery condition. Charge or replace as necessary. Connect load tester and ammeter according to tool manufacturer's instructions. With engine running at 2000 RPM and all accessories off, load system to determine generator voltage output. With engine running, turn A/C (if equipped) and headlights on, turn blower motor to high speed. Increase engine speed to 2000 RPM. Voltage should increase a minimum of .5 volt above base voltage.

GENERATOR NO-LOAD TEST

Verify battery condition. Charge or replace battery as necessary. Connect voltmeter positive lead to B+ terminal on generator and negative lead to ground. Start and run engine at 2000 RPM with all accessories off. Read voltmeter when voltage stabilizes. Voltage should be 13-15 volts. If voltage is not as specified, replace generator. See GENERATOR under REMOVAL & INSTALLATION.

RETRIEVING DIAGNOSTIC TROUBLE CODES

Connect New Generation Star (NGS) tester to Data Link Connector (DLC) and retrieve charging system Diagnostic Trouble Codes (DTCs). See POWERTRAIN CONTROL MODULE (PCM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX . If any other Diagnostic Trouble Code (DTC)s are present, see SELF-DIAGNOSTICS - EEC-V article in ENGINE PERFORMANCE to diagnose fault. After repair is complete, clear DTCs. See CLEARING DIAGNOSTIC TROUBLE CODES . If no DTCs are present, repair by symptom. See SYMPTOM INDEX table under SYSTEM TESTS.

POWERTRAIN CONTROL MODULE (PCM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX

CLEARING DIAGNOSTIC TROUBLE CODES

Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Using NGS tester manufacturer's instructions, clear Diagnostic Trouble Code (DTC)s.

TEST B: SYSTEM OVERCHARGES

1. Connect NGS tester. Turn ignition on and perform PCM self-test. If any Diagnostic Trouble Code (DTC)s are retrieved, see «POWERTRAIN CONTROL MODULE (PCM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX»(ref-4652-S34071923582000071200000) table. If no DTCs are retrieved, go to next step.
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 greater than 15 volts, go to step 4 . If voltage is less than 15 volts, go to next step.
3. Turn ignition off. Disconnect generator 3-pin connector. Start engine. Check generator output. See «GENERATOR LOAD TEST»(ref-4652-S42319342332000071200000) under ON-VEHICLE TESTING. If generator tests okay, go to next step. If generator does not test okay, replace generator. See «GENERATOR»(ref-4652-S07358835852000071200000) under REMOVAL & INSTALLATION.
4. Measure voltage of Red wire at generator 3-pin connector. If voltage is less than .5 volt from battery voltage, replace generator. See «GENERATOR»(ref-4652-S07358835852000071200000) under REMOVAL & INSTALLATION. Clear DTCs and retest system operation. If voltage is greater than .5 volt from battery voltage, repair high resistance in Red wire. See «WIRING DIAGRAMS»(ref-4652-S09740976542000071200000) . Clear DTCs and retest system operation.

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

1. Connect NGS tester. Turn ignition on and perform PCM self-test. If any Diagnostic Trouble Code (DTC)s are retrieved, see «POWERTRAIN CONTROL MODULE (PCM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX»(ref-4652-S34071923582000071200000) table. If no DTCs are retrieved, go to next step.
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 greater than 15 volts, perform «TEST B: SYSTEM OVERCHARGES»(ref-4652-S39917354702000071200000) . If voltage is less than 15 volts, go to next step.
3. Turn ignition off. Disconnect generator 3-pin connector. Turn ignition on. Measure voltage of Red wire at generator 3-pin connector. If battery voltage is present, go to next step. If voltage is not present, repair open or short in Red wire. See «WIRING DIAGRAMS»(ref-4652-S09740976542000071200000) . Retest system operation.
4. Turn ignition off. Disconnect PCM connector C175c. Turn ignition on and observe warning indicator. If warning indicator is illuminated, repair short to ground in Gray/Red wire between generator and PCM. See «WIRING DIAGRAMS»(ref-4652-S09740976542000071200000) . If warning indicator is not illuminated, go to next step.
5. Turn ignition off. Reconnect PCM connector C175c. Disconnect generator 3-pin connector. Check generator output. See «GENERATOR LOAD TEST»(ref-4652-S42319342332000071200000) under ON-VEHICLE TESTING. If generator tests okay, go to next step. If generator does not test okay, replace generator. See «GENERATOR»(ref-4652-S07358835852000071200000) under REMOVAL & INSTALLATION.
6. Disconnect PCM connector C175c. Inspect connector for pushed out pins, corrosion or bent terminals. Repair as necessary. If 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 D: WARNING INDICATOR OFF WITH IGNITION ON

1. Connect NGS tester. Turn ignition on and perform PCM self-test. If any Diagnostic Trouble Code (DTC)s are retrieved, see «POWERTRAIN CONTROL MODULE (PCM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX»(ref-4652-S34071923582000071200000) table. If no DTCs are retrieved, go to next step.
2. Turn ignition off. Disconnect NGS tester and generator 3-pin connector. Turn ignition on. Connect a fused (15-amp) jumper wire between generator 3-pin Gray/Red wire terminal and ground. If warning indicator illuminates, replace generator. See «GENERATOR»(ref-4652-S07358835852000071200000) under REMOVAL & INSTALLATION. If warning indicator does not illuminate, go to next step.
3. Disconnect PCM connector C175c. Inspect connector for pushed out pins, corrosion or bent terminals. Repair as necessary. If 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 FLICKERS, OR IS INTERMITTENT

1. Connect NGS tester. Turn ignition on and perform PCM self-test. If any Diagnostic Trouble Code (DTC)s are retrieved, see «POWERTRAIN CONTROL MODULE (PCM) DIAGNOSTIC TROUBLE CODE (DTC) INDEX»(ref-4652-S34071923582000071200000) table. If no DTCs are retrieved, go to next step.
2. Disconnect generator 3-pin connector. Inspect generator, battery and battery junction box for looseness, corrosion or bent terminals. Clean and tighten any loose connection. If connections are okay, reconnect generator 3-pin connector and go to next step.
3. Start engine. With engine running, inspect battery junction box fuse No. 415 (5-amp), by wiggling fuse and observing warning indicator. If warning indicator flickers, repair loose fuse connection. Retest system operation. If warning indicator does not flicker, go to next step.
4. With engine running and all accessories turned off, measure voltage between battery terminals. If battery voltage is greater than 15 volts, perform «TEST B: SYSTEM OVERCHARGES»(ref-4652-S39917354702000071200000) . If battery voltage is less than 15 volts, go to next step.
5. Turn ignition off. Disconnect generator 3-pin connector. Connect a fused (15-amp) jumper wire between generator 3-pin Gray/Red wire terminal and ground. Turn ignition on and observe warning indicator. If warning indicator illuminates, go to next step. If warning indicator does not illuminate, repair open in Gray/Red wire. See «WIRING DIAGRAMS»(ref-4652-S09740976542000071200000) . Retest system operation.
6. Turn ignition off. Connect generator 3-pin connector. Turn ignition on and observe warning indicator. If warning indicator illuminates, system is operating correctly at this time. Inspect circuits for intermittent opens or shorts. Retest system operation. If warning indicator does not illuminate, go to next step.
7. Disconnect PCM connector C175c. Inspect connector for pushed out pins, corrosion or bent terminals. Repair as necessary. If 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.