Classic/Antique Car Repair: All fired up! troulbleshooting electrical problem, fuel gauge, power antenna

Question
I have a 1980 corvette L82, sometimes the gauges all work and most only the eng temp and fuel gauge. When flashers are on the fuel gauge moves to full, also when pressing the brake pedal this happens with the car on or off. The clock works when the fuse is in, but the interior lights stay on and the power antenna motor stays on.

Answer
sounds like a combo of two or three problems

The fuel gauge issue is a problem of insufficient ground. This could also some of you other problems.

Also sounds like your have a short either in your wiring or the headlight switch itself.

Invest in a $3 electrical meter and check it out.