Not and expert, but I have recently reassembled my 73 Cuda that had been completely restored and painted top to bottom. You cannot believe the problems I had from the lack of a good ground. It showed up on everything electrical in the car. My wiper switch dimmed my dash lights, my amperage gauge wouldn't read correctly because the voltage regulator wasn't grounded to the fire wall, etc, etc, ect....bottom line is most of your problems will be settled by a good ground. I ended up running a couple of ground wires from my dash panel and my switch panel to my battery ground and all my my dash problems disappeared. Just my 2cents. Good luck, and let us know how it goes.
Sent from my iPad using Tapatalk