Electrical Issues

[CMT]

Hello. I'm working on a 1970 pro-touring trans am project. It's been a thorough rotisserie restoration. My problem is that the fuel and voltage gauges bounce all over the place. At a stop light they will pulse with the turn signal. I have brand new auto meter gauges, brand new wiring harness, LS-6 engine, new alternator. From what I can tell the car is grounded properly. Any ideas on how to fix this?

[130fe]

Sounds like all of the gauges and turn signal lights share the same ground for the dash. I had this with a a set of autometers I used to have in my car. Have the turn signal light ground all by itself and put the gauges in another ground location and your issue will go away.

[astroracer]

How is the alternator wired? 1 or 3 wire? If it's a 1 wire set up that will also cause gage fluctuation as the alternator is trying keep up with system voltage demands.
Mark

[CMT]

Thanks Chris and Mark. I'll check all of that out and get back to you with an update.

[blitzer454]

Also make sure that your dash ground is not electrically isolated from the body ground. You might be missing some ground straps somewhere.

[minendrews68]

From what I've encountered.. you can't have enough grounds. Just make sure they're the proper gauge wire. I have grounds from the body to the frame etc.