71 cuda all new wiring from Year One the car was restored in 2004.
I think it is the voltage regulator but not sure I replaced the regulator and it work for a couple of week. 15 miles.
The car started and ran with the new regulator.
the voltmeter in the car worked fine until I ran the car hard. Maybe reved the motor to 6000 rpm.
The voltmeter showed over charging then after a while it droped to the center. Not charging or discharging.
When I shut the car off it was dead. This is the same thing that happend with the original Voltage regulator.
The battery has a full charge but the car doesn't have any power going to it.
Not even the clock will run.
Then If I un hook the battery or the voltage regulator and reconnect it everything will work.
What is going on here? I didn't know that a voltage regulator could stop all power from leaving the battery.

I think my problem may be the amp meter. It is original. The lights don't go through the ignition switch and when it acts up even the lights and clock won't work.

try the ceramic resistor on the firewall first

Can't be ballast. As mentioned, bulkhead conn is #1 suspect, followed by fuse link and ammeter lugs.

Rick

I don't have a ballast resistor on my car. Also from what I remember with a bad ballast resistor the car will turn over the lights will work but it just won't fire.