Similar issue with mine. Start fine for days then dead, then start, then dead. When it wouldn't start I'd check voltage all the way from the battery to the bulkhead and it'd be fine. Then get inside and check the opposite side from the bulkhead to the ignition switch and get nothing at the bulkhead. Go back to the engine compartment for a second check and get nothing at the engine side of the bulkhead. WTH! An hour later she'd fire right up. When it happened one time and I kept getting nothing I started cutting the tape off the wiring bundle at the top of the firewall and found a butt connector splice, by the PO, and the wire pulled right out of one end. Recrimped it and all was well for a couple of weeks when it happened again. Wiggled the wire at the bulkhead and it pulled right out leaving the spade in the bulkhead. When I pulled the spade out the bulkhead plastic broke. It was melted badly. Gave up and did the bulkhead bypass and alternator mod. No more starting problem since.