Test U: Charge System Warning Never/Always On
- Turn ignition on. Wait until prove-out cycle is completed. If charge system warning indicator is always on, go to next step. If charge system warning indicator is never on, turn ignition off. Remove indicator bulb. Check for continuity between indicator bulb terminals. If continuity is not present, replace bulb. If continuity is present, go to next step.
- Turn ignition off. Disconnect alternator voltage regulator connector. Turn ignition on. Using a jumper wire, connect alternator connector Yellow/Black wire terminal to ground. If charging system indicator light comes on, fault is in alternator. If light does not come on, go to next step.
- Turn ignition off. Remove instrument cluster. See REMOVAL & INSTALLATION . Disconnect instrument cluster connector C276. See Figure . Locate diode junction box behind instrument cluster. See Figure . Remove Black diode strip from diode junction box 1. Measure resistance of Yellow/Blue wire between instrument cluster connector C276, pin No. 8 and diode junction box 1 connector C2011, pin No. 2. See Figure and Figure . Measure resistance of Yellow/Blue wire between ground and instrument cluster connector C276, pin No. 8. If resistance between instrument cluster connector and diode junction box 1 connector is less than 5 ohms, and greater than 10,000 ohms between instrument cluster connector and ground, go to next step. If resistances are not as specified, repair open or short in Yellow/Blue wire.
- Leave ignition off. Measure resistance of Yellow/Black wire between alternator voltage regulator connector and diode junction box 1 connector C2011, pin No. 5. Measure resistance of Yellow/Black wire between ground and diode junction box 1 connector C2011, pin No. 5. If resistance between alternator connector and diode junction box 1 connector is less than 5 ohms, and greater than 10,000 ohms between diode junction box 1 connector and ground, go to next step. If resistances are not as specified, repair open or short in Yellow/Black wire.
- Leave ignition off. Using ohmmeter, test Black diode strip by placing positive lead to connector C2011, pin No. 2 and negative lead to pin No. 5. If continuity is present, replace instrument cluster. If continuity is not present, replace Black diode strip.