A few days ago, I decided to completely replace the main ground lines in the rabbit. As you saw, they were very old and yucky. Probably not doing me any favors. Wasn’t sure where to go for this kind of thing, so I called up the local auto store, and they only had this gauge wire in 100 foot lengths, no good for a cheap project.
I decided to check out home depot, and you can buy 4 gauge for about $2 a foot, and the connectors for a reasonable price. I bought about 12 feet to redo the battery to frame, battery to transmission, battery to engine, etc.
I found out later that you can buy a complete earthing/grounding kit online for around $20. Probably should have looked more before I jumped into Home Depot, but my solution is pretty cool too.
So, this hasn’t solved the no-start problem, but at least I can rule out the main grounds.