Test Ch-48, Alternator Field Not Switching Properly
NOTE:
Perform TEST FC-1A, CHECKING SYSTEM FOR FAULT CODES before proceeding.
- Turn ignition on, engine off. Using DRB-II, actuate ASD fuel system. Put DRB-II in voltmeter mode and probe ASD relay output terminal (Dark Green/Orange wire) at rear of alternator. See Fig 1. If voltage is less than 10 volts, repair open in Dark Green/Orange wire circuit to alternator. After repair is complete, perform TEST VER, VERIFICATION PROCEDURE .
- If voltage is more than 10 volts, probe field terminal (Dark Green wire) at rear of alternator. If voltage is more than 10 volts, go to step 3). If voltage is less than 10 volts, go to step 5).
- Using DRB-II, stop ASD fuel system actuation test. Turn ignition off. Disconnect and inspect PCM connector and pins. Disconnect and inspect alternator field circuit connector at rear of alternator. See Fig 1. If any connector is damaged, repair or replace as necessary. After repair, perform TEST VER, VERIFICATION PROCEDURE .
- If all connectors are okay, leave PCM and alternator field circuit connectors disconnected. Using an external ohmmeter, connect one lead to field terminal (Dark Green wire) of field circuit connector and connect other lead to PCM connector terminal No. 20. See Fig 2. If resistance is less than 5 ohms, replace PCM. After repair, perform TEST VER, VERIFICATION PROCEDURE . If resistance is more than 5 ohms, repair open in Dark Green wiring circuit. After repair, perform TEST VER, VERIFICATION PROCEDURE .
- Using DRB-II, stop ASD fuel system actuation test. Turn ignition off. Disconnect and inspect PCM connector and pins. Disconnect and inspect alternator field circuit connector at rear of alternator. If any connector is damaged, repair or replace as necessary. After repair, perform TEST VER, VERIFICATION PROCEDURE .
- If all connectors are okay, leave alternator field circuit connector disconnected. Using an external ohmmeter, connect one lead to field terminal and one lead to ignition terminal at rear of alternator. If resistance reading is more than 5 ohms, replace alternator. After repair, perform TEST VER, VERIFICATION PROCEDURE .
- If resistance reading is less than 5 ohms, put DRB-II in ohmmeter mode. Probe DRB-II lead to alternator field circuit connector field terminal (Dark Green wire). If resistance reading is more than 5 ohms, replace PCM. After repair is complete, perform TEST VER, VERIFICATION PROCEDURE . If resistance reading is less than 5 ohms, repair short to ground in Dark Green wire circuit. After repair, perform TEST VER, VERIFICATION PROCEDURE .