INTERMITTENT IGNITION ISSUE
All of the above. I would temp wire up a pilot lamp AND voltmeter to the common junction of the ignition "run" line in the engine bay. Get a diagram so you can follow it. The "run" line comes out of the bulkhead connector, and at some point branches to feed the ballast resistor, the VR, alternator field, electric choke if used, and on certain later models, a couple of smog doo dads. Monitor that and see what you find
You can also check it in your shop, "wiggle test" the bulkhead connector, the harness under the dash, and reach up and wiggle the ammeter connections.
The diagram on the ammeter article by MAD electrical is a good one to show you the simplified path.
The diagram below is VERY VERY important to understand the functional path of power all the way from battery to ignition. What is now shown here, is the last two or three terminal points, AKA the "run" wire feeding back out into the engine bay, through the bulkhead, and the splice/ terminals at the ballast resistor. ANY POINT where there is a connector/ terminal/ splice/ switch contact can be a problem, and there of course can be MORE than one
http://www.madelectrical.com/electricaltech/amp-gauges.shtml
All of the above. I would temp wire up a pilot lamp AND voltmeter to the common junction of the ignition "run" line in the engine bay. Get a diagram so you can follow it. The "run" line comes out of the bulkhead connector, and at some point branches to feed the ballast resistor, the VR, alternator field, electric choke if used, and on certain later models, a couple of smog doo dads. Monitor that and see what you find
You can also check it in your shop, "wiggle test" the bulkhead connector, the harness under the dash, and reach up and wiggle the ammeter connections.
The diagram on the ammeter article by MAD electrical is a good one to show you the simplified path.
The diagram below is VERY VERY important to understand the functional path of power all the way from battery to ignition. What is now shown here, is the last two or three terminal points, AKA the "run" wire feeding back out into the engine bay, through the bulkhead, and the splice/ terminals at the ballast resistor. ANY POINT where there is a connector/ terminal/ splice/ switch contact can be a problem, and there of course can be MORE than one
http://www.madelectrical.com/electricaltech/amp-gauges.shtml