1313

the battery gauge will usually go far to plus side then settle back to just plus of the center line. today it started dancing all over ... what was strange was ---as i was sitting there with the door open i could watch the same dancing pattern with the interior lites....like they were keeping time.it never smothed
out even while driving to work ....help

Cajun99

Earlier this month while I was in a Christmas parade my '75 started doing the same thing. I prayed the car would make it through the day before crappin' out. It did.

The next day I took the easy way out and replaced the alternator. Problem fixed. You could have one of a myriad of issues in your electrical system. I got lucky with an easy fix. :yesnod:

63Banshee

The lights will dim as the battery current is drawn to the short circuit in the electrical system. It could very well be an alternator/regulator issue or a short in the wiring. I'd test the alternator first since it's a free test at your auto parts store.

MikeE.79

sounds like a bad voltage regulator to me!

Mike

63Banshee

Is the regulator not internal on mid 70 Vettes?

Rockn-Roll

Sounds like a loose ground. Unfortunately there are a lot of grounds on the car. Check the ground wire running to the alternator. There's also a bundle of ground wires at the front of the center console including a ground wire for the gauges and interior lights.

63Banshee

I thought this too at first, but he makes it sound like the needle is going far into the negative. This would indicate battery drainage due to a short.

1313

thanks for the help so far... the gauge is bouncing to the positive side only.
interior lites, dash lites all flicker with the gauge