Test TC-50A, Alternator Field Not Switching Properly
WARNING: This page is about a different car, the 1994 Eagle Vision, 1994 Dodge Intrepid, 1994 Chrysler New Yorker, 1994 Chrysler LHS, and 1994 Chrysler Concorde. However, it is still accessible from the selected car via links, so may be relevant.
NOTE:
After repair, perform TEST CH-VER, VERIFICATION PROCEDURE .
- Turn ignition on, engine off. Using DRB, actuate Auto Shutdown (ASD) fuel system. Using DRB in voltmeter mode, backprobe ASD relay output terminal (Dark Green/Orange wire) at rear of alternator. See Figure. If voltage is less than 10 volts, repair open in Dark Green/Orange wire to alternator.
- If voltage is more than 10 volts, backprobe field terminal (Dark Green wire) at rear of alternator. If voltage is more than 10 volts, go to next step. If voltage is less than 10 volts, go to step 5).
- Using DRB, stop ASD fuel system actuation test. Turn ignition off. Disconnect and inspect Powertrain Control Module (PCM) connector and terminals. PCM is located under air cleaner. Disconnect and inspect alternator field circuit connector at rear of alternator. See Figure. If any connector is damaged, repair or replace as necessary.
- If all connectors are okay, leave PCM and alternator field circuit connectors disconnected. Using an external ohmmeter, check resistance of Dark Green wire between alternator field circuit connector and PCM connector terminal No. 20. (Dark Green wire). See Fig 1. If resistance is less than 5 ohms, replace PCM. If resistance is more than 5 ohms, repair open in Dark Green wire.
- Using DRB, stop ASD fuel system actuation test. Turn ignition off. Disconnect and inspect PCM connector and terminals. PCM is located under air cleaner. Disconnect and inspect alternator field circuit connector at rear of alternator. If any connector is damaged, repair or replace as necessary.
- 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 ASD relay output terminal at rear of alternator. If resistance is more than 5 ohms, replace alternator.
- If resistance is less than 5 ohms, put DRB in ohmmeter mode. Probe alternator connector field terminal (Dark Green wire). If resistance is more than 5 ohms, replace PCM. If resistance is less than 5 ohms, repair short to ground in Dark Green wire.