67Dart273 said

You can, if you do, use it to also feed the regulator IGN terminal. It is quite common in these old cars for the bulkhead connector and other points in the harness to be a problem.

Read this Mad article for insight:

http://www.madelectrical.com/electricaltech/amp-gauges.shtml

The diagram down that page shows clearly the problem points in the harness:

The path (follow the diagram)

is from the battery (red wire) --fuse link-- bulkhead connector -- ammeter-- through the meter -- out the ammeter -- to the in harness welded splice -- branch off to ignition switch connector (not pictured) -- through the ignition switch -- back out the switch connector -- back out the bulkhead connector on the "igntion run" or "IGN1" buss, which feeds

ignition run voltage to the "key" side of the ballast,

the regulator IGN terminal

On 70 and later cars, it also feeds a few other things, the alternator blue field lead, electric choke if used, and some smog doo dads on some cars.

Both the red and black bulkhead connector terminals can develop problems as described in the MAD article, but the blue "ignition run" terminal can, also.

Click to expand...