Ground wires

All good advice. Look at your passenger side head where the alternator mounts. Those same bolt holes are on the rear of the driver side head. Buy a 1 ft long "starter cable" IE "ring terminal to ring terminal" no4 cable. Bolt it to the rear of the head with a short bolt, and the other end to one of the master cylinder studs.

And as wjajr said, the bulkhead connectors are becoming a huge problem