I have an 87 Trans Am. I replaced the altenator on it but the guage floats between low an not quit to 13 on the gauge. Has anyone else seen this problem and what was the fix for it? Any advice would be very helpful.

 

Had that problem on my 89 Z71 truck. It has the same alternator as our TPI cars and mine turned out to be a cheap rebuilt autozone alternator. A friend of mine worked in a rebuilding shop and went through it and it went to 14.4 instead of 11.5 I am currently trying to change to a CS144 but cannot find a core so my buddy can rebuild it.

 

Check your charge wire for internal corrosion. This will cause low voltage or a voltage fluctuation. Take it off and try to bend it. If it cracks or powder comes out, replace it with a larger gauge wire.