Generator System Check

When operating normally, generator indicator lamp will come on when ignition is in RUN, and go out when engine starts. If lamp operates abnormally or if an undercharged or overcharged battery condition occurs, following procedure may be used to diagnose charging system. Remember that an undercharged battery is often caused by accessories being left on overnight, or by a defective switch that allows a lamp, such as a trunk lamp or a glove box lamp, to stay on.

Diagnose generator with following procedure:

1. Visually check belt and wiring. With ignition in RUN and engine stopped, charge indicator lamp should be on. If not, detach harness at generator and ground "L" terminal in harness with a fused 5-ampere jumper lead. If lamp lights, replace generator. If lamp does not light, locate open circuit between ignition switch and harness connector. The indicator lamp bulb may be burned out.
2. With ignition switch in RUN position and engine running at moderate speed, charge indicator lamp should be off. If not, detach wiring harness at generator. If lamp goes off, replace generator. If lamp stays on, check for a short to ground in harness between connector and indicator lamp.
   NOTE: Always check generator for output before assuming that a grounded "L" terminal circuit has damaged regulator.