There will be at least 2 seperate grounds on the rear of the intake manifold. A 10 or 12 gauge black wire by itself and a small black with a small tan wire together on the same ring terminal. Then there should be a flat ground strap that goes to the firewall. There will be another flat ground strap that goes to the frame by the downpipe . The flat straps are sometimes bolted to the back of the passenger side head. You won't be able to get to the frame ground by the downpipe. Be shure to check every fuse in the underhood fusebox and on the side of the dash by the drivers door.