I recently bought a 1989 305 TBI manual Camaro a couple weeks ago. The tach is pegged at 7000rpm but the rest of the gauges still work. Sometimes when I turn on the car the tach will jump back to about 3000rpm and then pegg back at 7000rpm. I've searched about the tach and read that they eventually go out and in order to fix it I just need to find another one that works and put it in.

Now for the weird part. When I am driving around at night with the lights on of course the right side of the cluster will shut off. Meaning the bulbs, oil pressure, battery, and the tach would still be messed up. Plus the right turn indicator will stay lit. If I turn off my lights they function correctly.

Is the whole cluster shot? Or is it something else? I also have a 145mph cluster I got from the junkyard about a week ago, but have not put it in yet. I want to see if this is a cluster problem or something else.

Has anybody experienced this before?

 

Is it possible that the cluster has been removed/replaced at some point and simply isn't seated correctly?

JamesC

 

I guess that could be possible. But I still don understand why the right side eventually shuts off at night and turning off my headlights will restore the gauges. When I get time I will put in the 145mph cluster and see what happens.

Back to the tach, I recently noticed when I turn on the car it jumps from 7 grand to 3 grand and then back to 7 grand. I'm not sure if that helps to diagnose the problem.

 

Just to give a little update, the right side of the cluster so far has not shut off with the lights on with the new one in. I still need to find a new tach.