Doc here
imp:
Check all your grounds.
Run a properly gauged Ground cable from the battery to any handy bolt at or near the starter, From that same Block bolt get a Battery cable at the parts store, that has two 3/8 ring terminals on each end and attach it there and to the Frame.
Next get some 10 gauge wire and ring terminals and run that from your Block bolt on the block to the Firewall, and another Separate wire to the Alternator bracket, Lug or mount bolt.
Next get some Wire Braid, (Radio Shack) and install braid from the radiator support to the frame, Fenderwells to frame , hood to firewall, Doors to door posts, gas flap to body, tailgate / Trunk to body.
At each point the wire is grounded, Burnish ALL the paint and grease off to bare metal. Use a proper star-washer and lock. Use sheetmetal or Tech screws where no screws are available.
It sounds like a lot of work, but after you assemble all the parts, it's only a few hours to do..and you'll end up with a system that will work reliably for many years to come..and can eliminate that from your troubleshooting list.
Doc
imp:
