Electrical or ground issue?

Thanks yes. We MacGuyvered a couple of the wires going into the bulkhead as I didn't have the proper ends. Just used male tab type leads and jammed them in. Two in the middle top row of the bulkhead connector in particular.
A good crimper and leads is really really worth it.
Packard 56 male terminals are a close match for the bulkhead disconnects.
Packard 58 female terminals are a close match for the firewall side of the connector. PICO canada also sells Chrysler style female terminals.
For the connector seals, contact DMT.