I was having all sorts of weird electrical issues and had a tough time figuring it out. Got a high performance battery and replaced the engine ground strap and did all sorts of searching under the dash.

Basicaly the car was running fine but it seemed as though the power was dropping. Radio would cut out, speedo would cut off.

Turned out the problem was rust had built up under the negative power cable and not making a good connection to the body. Finaly noticed tiny sparks jumping when I was looking under the hood in the dark.

But yeah who would have thought of that HAHA.