Measure the voltage on the output wire and the red small wire plugged into the side of the case. If you have battery voltage, (11.5 volts) on the output terminal, that circuit is okay. There should be around 2.0 volts on the small wire if the battery light is on. That is the turn-on signal for the internal voltage regulator. If both of those voltages are there, replace the generator.
These are a real poor design and it is common to go through four to six of them in the life of the car. What many professionals are finding out is to reduce the repeat failures, replace the perfectly good battery, as you already did, at the same time. As they age, they lose their ability to dampen and absorb the huge voltage spikes these generators produce due to their design. The old battery will work fine in a pre-1987 vehicle.
Friday, April 22nd, 2011 AT 12:16 AM