66 barracuda ignition problem

You probably don't want to hear this, but it might be time to rewire the car. Now having said that, "wire" is rarely the problem, but connectors almost always are.

The bulkhead connector, ignition switch connector, headlight switch connector, headlight harness, dimmer, and fuse panel are all right up there with melt damage, corrosion and just plain old age.

I've always liked ammeters, but frankly, after I got my 67 a few years ago, I finally realized "it was time" and rewired the car without one, adding a voltmeter conversion in it's place.

Lastly a relay/ fuse panel out of a Voyager under the hood for several loads, pump, headlights, EFI, etc, has relieved strain on the interior portion and ignition switch.