The other day I was drving around and all my warning lights came on, I revved the motor up and the lights went off. The next day I was driving around and the lights came on but not very bright and they flicker according to engine idle speed. In key position 2 only my oil light comes on. But i know the oil light has nothing to do with the alternator. So is my problem wiring? or the entire alternator? the belts are tight, the connections are good at the alternator. Im just really confused if its not getting ground and if thats it, which wire is the ground. The fat red or the thin red and where do they go to? Then i came upon this post, so is it the burshes?

My newest brick is a 1988 244GL, which I mention as things do change, and your 1989 may be different from mine. I have the Volvo Wiring Diagram book for 1988.

When the key reaches Position II, sometimes called "Bulb check" postion, five warning lights should light up. Oil pressure, Parking brake, Brake failure, Altenator, and Bulb failure warning system.

After the engine starts and runs, all should go out. The oil pressure light was on because with no pressure it grounds through the sensor. Pressure = no ground = no light.

The other four have their ground through the alternator brushes. When the alternator begins charging, the ground is lost so the lights go dark.

The alternator brushes and voltage regulator are in a single unit, bolted to the rear of the alternator and easily replaced. The job can be done on the car; having the oil filter removed makes it much easier. Also an electric screwdriver is invaluable. Need a mirror and flashlight, too.

Order the part from fpcgroton or your favorite dealer.

The symptoms are those of worn out brushes. They should be 5mm minimum, and they are usually worn in 100,000 miles.