Charging System - Generators & Regulators: Diagnosis Ford Expedition II

TROUBLE SHOOTING

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

Ensure connections at generator, regulator and engine ground are clean and tight. Ensure battery posts and cables are clean and tight. Inspect drive belt. Inspect central junction box fuse No. 34 (15-amp). Inspect fusible links. Check all connections for looseness or corrosion. If problem is found, repair as necessary. If problem is not found, see SELF-DIAGNOSTIC SYSTEM .

ON-VEHICLE TESTING

Note. Battery posts and cable clamps must be clean and tight for accurate meter indications.

Note. Before performing on-vehicle testing, turn off all accessories and lights. Place vehicle in Neutral and apply parking brake.

BATTERY TEST WITH DIGITAL BATTERY ANALYZER

Connect digital battery analyzer to battery and follow on screen instructions. If battery test good, return to service. If battery does not test good, replace battery.

BATTERY DRAIN TEST

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. Note amperage draw. Draw will vary from vehicle to vehicle depending on the equipment package. Compare to a similar vehicle for reference. No factory equipped vehicle should have more than a 24-26 mA draw (0.024-0.026 amp).
5. If excessive current draw is present, 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.
6. 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.

GENERATOR LOAD TEST

1. 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 75 amps, with engine at 2000 RPM.
2. If voltage is as specified, system is operating properly at this time. If voltage is not as specified, see «SYMPTOM INDEX»(ref-165155-S34521056832004082000000) table under SYSTEM TESTS.

GENERATOR NO-LOAD TEST

1. Switch tester to voltmeter function. Connect voltmeter positive lead to B+ terminal on generator and negative lead to ground. Turn all electrical accessories off. Start and run engine up to 2000 RPM. Read voltmeter when voltage stabilizes. Voltage should be 13-15 volts.
2. Turn A/C system on. Turn blower speed to high. Turn headlights on to high beams. Voltage should increase a minimum of .5 volt. If voltage is not as specified, go to «SYMPTOM INDEX»(ref-165155-S34521056832004082000000) table under SYSTEM TESTS. If voltage is as specified, charging system is operating normally.

SELF-DIAGNOSTIC SYSTEM

Note. All diagnostic tests are written specifically for New Generation Star (NGS) tester. Most generic OBD-II compliant scan tools should be able to perform all test procedures.

RETRIEVING & CLEARING DIAGNOSTIC TROUBLE CODES

For retrieving and clearing DTCs, see SELF-DIAGNOSTIC SYSTEM in appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.

Using NGS tester, perform PCM self-test. Perform appropriate test under SYSTEM TEST in accordance with DTC retrieved. See POWERTRAIN CONTROL MODULE DIAGNOSTIC TROUBLE CODE INDEX table. Codes listed in this table are only for testing covered in this article. For complete DTC listing, see DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS in ENGINE PERFORMANCE. If no DTCs are retrieved, repair by symptom. See SYMPTOM INDEX table under SYSTEM TESTS.

POWERTRAIN CONTROL MODULE DIAGNOSTIC TROUBLE CODE INDEX

TEST A: BATTERY IS DISCHARGED OR VOLTAGE IS LOW

1. Check Battery Condition Test battery condition. See «BATTERY TEST WITH DIGITAL BATTERY ANALYZER»(ref-165155-S24688149612004082000000) under ON-VEHICLE TESTING. Is the battery okay? If yes, go to next step. If no, replace battery.
2. Check Generator Output Perform generator load and no-load tests. See «GENERATOR LOAD TEST»(ref-165155-S02893985842004082000000) and «GENERATOR NO-LOAD TEST»(ref-165155-S07642745092004082000000) under ON-VEHICLE TESTING. Is the generator okay? If yes, go to next step. If no, perform «TEST B: WARNING INDICATOR IS ON WITH ENGINE RUNNING, SYSTEM IS NOT CHARGING»(ref-165155-S32326760042004082000000) .
3. Check For Current Drains Perform «BATTERY DRAIN TEST»(ref-165155-S06434611032004082000000) under ON-VEHICLE TESTING. Are there any excessive current drains? If yes, repair as necessary. If no, go to next step.
4. Check Vehicle Grounds Start engine. Measure voltage drop between generator housing and negative battery terminal. Is the voltage drop less than 0.1 volt? If yes, go to next step. If no, check engine ground and battery for corrosion. Repair as necessary.
5. Check Voltage Drop In B+ Circuit (Black/Orange wire) Turn headlamps on high beam, heated rear window on (if applicable) and blower motor to high. With engine at approximately 2000 RPM, measure voltage drop between the generator B+ connector (Black/Orange wire) and positive battery terminal. Is the voltage drop less than 0.5 volt? If yes, go to «TEST B: WARNING INDICATOR IS ON WITH ENGINE RUNNING, SYSTEM IS NOT CHARGING»(ref-165155-S32326760042004082000000) . If no, high resistance in B+ circuit (Black/Orange wire). Test the system for normal operation.

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

1. Check Generator B+ Circuit (Black/Orange Wire) Turn ignition off. Measure the voltage between the generator B+ connector (Black/Orange wire) and ground. Is the voltage equal to battery positive voltage? If yes, go to next step. If no, repair the circuit. Test the system for normal operation.
2. Check Generator "A" Circuit (Orange/Light Blue) Measure the voltage between the generator connector terminal No. 3 (Orange/Light Blue wire) and ground. (Scheme 1) Is the voltage equal to battery positive voltage? If yes, go to next step. If no, repair the circuit. Test the system for normal operation.
3. Check Circuit 1931 (Brown/Pink Wire) For Voltage Disconnect generator 3-pin connector. Start engine. Measure the voltage between the generator connector terminal No. 1 (Brown/Pink wire) and ground. (Scheme 1) Is the voltage 8-12 volts? If yes, go to step 5. If no, go to next step.
4. Check Circuit 1931 (Brown/Pink Wire) For Integrity Turn ignition off. Disconnect PCM connector C175b. Measure the resistance between the generator connector terminal No. 1 (Brown/Pink wire) and the PCM connector C175b terminal No. 14, and between the generator connector terminal No. 1 (Brown/Pink wire) and ground. (Scheme 1)and (Scheme 2). Is the resistance less than 5 ohms between the generator and the PCM; and greater than 10,000 ohms between the generator and ground? If yes, install a new PCM. See COMPUTERIZED ENGINE CONTROLS in appropriate REMOVAL & INSTALLATION article in ENGINE PERFORMANCE. If no, repair the circuit. Test the system for normal operation.
5. Check Voltage Drop In B+ Circuit (Black/Orange Wire) Turn ignition off. Reconnect generator 3-pin connector. Start engine. Turn the headlamps on high beam, the heated rear window on (if applicable) and the blower motor to high. With the engine at approximately 2000 RPM, measure the voltage drop between the generator B+ connector (Black/Orange wire) and the positive battery terminal. Is the voltage drop less than 0.5 volt? If yes, install a new generator. See «GENERATOR»(ref-165155-S19998990132004082000000) under REMOVAL & INSTALLATION. If no, repair the high resistance in the B+ circuit (Black/Orange wire). Test the system for normal operation.

Scheme 1

Scheme 2

TEST C: SYSTEM OVERCHARGES (GREATER THAN 15.5 VOLTS)

1. Check For Fault Codes In PCM Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition switch to RUN position. Using NGS tester, perform Powertrain Control Module (PCM) self-test. If no DTCs exist, go to next step. If any DTCs exist, perform appropriate test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS in ENGINE PERFORMANCE.
2. Check Battery Voltage Turn ignition off. Disconnect the diagnostic tool. Start engine. With the engine running and all accessories turned off, measure the voltage at the battery while varying the engine RPM. Is the voltage greater than 15.5 volts? If yes, go to next step. If no, go to step 4.
3. Check For Voltage Drop In Circuit 35 (Orange/Light Blue Wire) Turn ignition off. Disconnect: generator 3-pin connector. Measure the voltage between the generator connector terminal No. 3 (Orange/Light Blue wire), harness side and ground. (Scheme 1) Is the voltage within 0.5 volt from battery voltage? If yes, reconnect generator connector and go to next step. If no, repair the circuit for high resistance. Test the system for normal operation.
4. Check Generator & Battery Ground Connections Turn ignition off. Check the ground connections between the generator and the engine, and the battery and the engine. Are all ground connections clean and tight? If yes, install a new generator. See «GENERATOR»(ref-165155-S19998990132004082000000) under REMOVAL & INSTALLATION. Clear the DTCs. Test the system for normal operation. If no, repair the ground connections as necessary. Clear the DTCs. Test the system for normal operation.

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

1. Check For Fault Codes In PCM Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition switch to RUN position. Using NGS tester, perform Powertrain Control Module (PCM) self-test. If no DTCs exist, see appropriate ANALOG INSTRUMENT PANELS article in ACCESSORIES & EQUIPMENT. If any DTCs exist, perform appropriate test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS in ENGINE PERFORMANCE.

TEST E: WARNING INDICATOR IS OFF WITH IGNITION ON

1. Check For Fault Codes In PCM Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition switch to RUN position. Using NGS tester, perform Powertrain Control Module (PCM) self-test. If no DTCs exist, go to next step. If any DTCs exist, perform appropriate test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS in ENGINE PERFORMANCE.
2. Check Charging System Warning Indicator Operation Turn ignition off. Disconnect the New Generation Star (NGS) tester. Disconnect generator 3-pin connector. Turn ignition on. With the engine off, connect a fused (15A), jumper wire between the generator connector terminal No. 1 (Brown/Pink wire) and ground. Does the charging system warning indicator illuminate? If yes, install a new generator. See «GENERATOR»(ref-165155-S19998990132004082000000) under REMOVAL & INSTALLATION. Test the system for normal operation. If no, go to next step.
3. Check For Correct PCM Operation Check for corrosion and pushed-out pins. Connect any disconnected connectors. Make sure all other system connectors are fully seated. Operate the system and verify the concern is still present. Is the concern still present? If yes, install a new PCM. See COMPUTERIZED ENGINE CONTROLS in appropriate REMOVAL & INSTALLATION article in ENGINE PERFORMANCE. Repeat the PCM self-test. If no, the system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. Clear the DTCs. Repeat the self-test.

TEST F: WARNING INDICATOR FLICKERS OR OPERATES INTERMITTENTLY

1. Check For Fault Codes In PCM Connect New Generation Star (NGS) tester to Data Link Connector (DLC). Turn ignition switch to RUN position. Using NGS tester, perform Powertrain Control Module (PCM) self-test. If no DTCs exist, go to next step. If any DTCs exist, perform appropriate test. See DIAGNOSTIC TROUBLE CODE DEFINITIONS in appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
2. Check For Loose Connections Disconnect generator 3-pin connector. Check all generator, battery, and power distribution connections for looseness, corrosion, loose or bent terminals, or loose eyelets. Connect generator 3-pin connector. Are all connections clean and tight? If yes, go to next step. If no, repair as necessary. Test the system for normal operation.
3. Check Fuse Connection Start engine. With the engine running, check central junction box fuse 9 (10A) in circuit 35 (Orange/Light Blue wire) for looseness by wiggling the fuse and noting the charging system warning indicator lamp operation. Does the charging system warning indicator lamp flicker? If yes, repair loose fuse connections as necessary. Test the system for normal operation. If no, go to next step.
4. Check Battery Voltage Start engine. With the engine running, and all accessories turned off, measure the voltage at the battery while varying the engine RPM. Is the voltage greater than 15.5 volts? If yes, go to «TEST C: SYSTEM OVERCHARGES (GREATER THAN 15.5 VOLTS)»(ref-165155-S41613115612004082000000) . If no, go to next step.
5. Check Warning System Indicator Operation Turn ignition off. Disconnect generator 3-pin connector. Turn ignition on. Connect a fused jumper wire between generator connector terminal No. 1 (Brown/Pink wire) and ground. Does the charging system warning indicator illuminate? If yes, go to next step. If no, repair the circuit. Test the system for normal operation.
6. Check PCM Operation Turn ignition off. Connect generator 3-pin connector. Turn ignition on. Monitor the charging system warning indicator operation. Is the charging system warning indicator illuminated? If yes, the PCM is operating correctly. Recheck the generator circuits (including the generator) for intermittent shorts or opens. Test the system for normal operation. If no, go to next step.
7. Check For Correct PCM Operation Check for corrosion and pushed-out pins. Connect any disconnected connectors. Make sure all other system connectors are fully seated. Operate the system and verify the concern is still present. Is the concern still present? If yes, install a new PCM. See COMPUTERIZED ENGINE CONTROLS in appropriate REMOVAL & INSTALLATION article in ENGINE PERFORMANCE. Repeat the PCM self-test. If no, the system is operating correctly at this time. Concern may have been caused by a loose or corroded connector. Clear the DTCs. Repeat the self-test.

TEST G: GENERATOR NOISY

1. Check For Accessory Drive Noise & Mounting Brackets Check the accessory drive belt for damage and correct installation. Check the accessory mounting brackets and generator pulley for looseness or misalignment. Is the accessory drive okay? If yes, go to next step. If no, repair as necessary. Test the system for normal operation.
2. Check Generator For Electrical Noise Disconnect generator 3-pin connector. Start engine. With the engine running, is the noise still present? If yes, go to next step. If no, install a new generator. See «GENERATOR»(ref-165155-S19998990132004082000000) under REMOVAL & INSTALLATION. Test the system for normal operation.
3. Check Generator For Mechanical Noise Turn ignition off. Start engine. Turn all accessories off. With the engine running, use a stethoscope or equivalent listening device to probe the generator for unusual mechanical noise. Is the generator the noise source? If yes, install a new generator. See «GENERATOR»(ref-165155-S19998990132004082000000) under REMOVAL & INSTALLATION. Test the system for normal operation. If no, diagnose the source of the engine noise.

TEST H: RADIO INTERFERENCE

1. Verify Generator Is Source Of Radio Interference Start and run the engine. Tune the radio to a station where the interference is present. Turn ignition off. Disconnect: generator B+ connector (Black/Orange wire). Start engine. With the engine running, is the interference present with the generator disconnected? If yes, diagnosis in-vehicle entertainment system. If no, replace generator. See «GENERATOR»(ref-165155-S19998990132004082000000) under REMOVAL & INSTALLATION.