Thanks for all the tips everyone...I've had a lot of strange voltage drops in this car for the two years I've owned it and it's time to start correcting them. For example, I turn on the halogen interior light and the voltmeter drops from 12.5v to 10.8v, sometimes but not always. Same with the parking lights, same with the brake lights...always sometimes but not always.

When I connect a ground to the frame, am I going to have to tap and drill a hole or are there some natural points up front for this.