1st you need to fill in the gaps...
What year?
What electrical modifications?
What does "always restarts and runs perfectly when the plugs get cleaned off"
mean? What Plugs?
What does "Shuts down everything electrical"
mean? does the radio shut off? the headlights turn off? the Wipers stop? the turn signals stop?
Sounds to me like you have a bad connection that is opening on a bump. If it was a short you would have melted wires by now.
The path is basically...
from alternator to bulkhead connector to ammeter to bulkhead connector to post on starter relay to battery.
along the way to the Ammeter there is a splice that feeds the car and everything in it.
View attachment 1716118532
View attachment 1716118534
THE MAIN SUSPECTS
The connections at the Bulkhead connectors
The Ignition Switch and its connections
The main Splice
If you haven't already go to
Mymopar.com and download your cars Service manual. (free download)
go to
cllasiccarwiring.com and buy a colored wiring diagram (best $25.00 you will spend)
