I'm hunting down some electrical oddities while looking to install a new radio requiring two hot connections; 1 constant and 2 other is when ignition key is on. The common advice is to check all grounding connections or even add some. As I understand less than 1.0 ohms or 0.5 volts indicates a good ground; lower the better. I added another ground from the neg battery clamp to the fender wall. Where are the motor to chassis connections and any other for the body on this car such as body to frame? The factory manual doesn't indicate locations as far as I can tell. Appreciate any advice.