[Imposter71]

Hello, having some elec gremlins and could use direction/suggestions...

71 Lemans Sport, 350, stock harness.

Thought car was running hot and didn't trust just the warning light in the dash so I installed aftermarket electrical (numbered) temp gauge. Every time I step on brake, hit turn sig, lights, heater blower fan,etc - the gauge jumps up. Noticed yesterday that it appears in the tach as well but it usually drops or bounces around. Happens on both gauges when I hit/use any of the above mentioned items( brake, signals, lights,etc).

Battery does not drain when the car sits.

Any suggestions?

Could this be a short to graound on a main power wire feeding the fuse box? If so what color is that wire and where should I start traceing it from?

Any help/suggeatins are greatly appreciated.