Attention: All B-Body owners, the wire going from the negative battery terminal to the body is a likely cause of any electrical problem you may have. And if you don’t have any problems now, I still strongly suggest you still fix the problem before it happens. The wire going from the negative battery terminal to the body attaches to the body with a stupid sheet metal screw and a star washer. The only real surface to conduct electricity comes from the screw cutting into the hole. This may be OK for the first ten years, but after it gets a little dirty (i.e. slight corrosion or rust), the ability of this connection to conduct electricity is severely compromised. The end result is the negative ground problems that these cars have (in my opinion).
My fix was to use a bolt thru one of the existing holes already near the battery. I sanded off the paint to get down the bare metal. I used a fender washer to make sure I had a good contact between the bolt & the body. I then used one of the side post bolts that have a stud on the end of it and ran two 10 awg wires from the battery terminal bolt to my special grounding bolt. Now all the circuits in the car have a good solid connection to negative side of the electrical system! This connection feeds everything except for what is attached to the engine (i.e. starter & alternator).
I have for several months been having a bad issue with the car not wanting to start. It would turn over very slow and half the time it would just click. These are classic signs of a low battery or a starter that pulls too much current. I checked all three: the battery, starter, & alternator. They all tested fine. I was at my wits end. I had swapped in three different batteries from my other cars and even removed the starter and had it checked at two separate shops. Every test passed and the car still started extremely slow …when it started!
I got to looking around at the battery (for the 20th time) and saw what appeared to be two wires from the negative terminal to the body ground. Upon closer inspection, I found that the insulation burned off of the wire and made it look like it had two wires. Burned copper wire will conduct electricity, but not too good. I bet this problem has caused my fuel pump wires to burn and the turn signal switch to fail and is most likely the reason why I have never had all the brake lights working!
Just wanted to share the information with others that may not know this, but I suspect the guys that have been around for awhile have known this problem for years. So I don’t mean to come off like I discovered a new planet… Good luck, Shimaze
