Well I nearly mentioned........and I will...........this problem might well be simply a bad ignition switch. How do you have the alternator output connected, that is the big stud?
One to the Starter Relay, another goes through the bulkhead (no connecters) and meets with the former ammeter Red wire at a new spade fusebox input (MADD electric) Bypass. I'm thinking ignition switch as there are no definitive clicks for accessory, off just the momentary contact for start/run. The only way you know you would be in off is because the key comes out and it's at 12:00 position.
