What is "2v at the fuse?" Fuse link up by the starter relay? You have likely found it, either the link is AFU internally, corrosion, etc, or a bad connection right there such as the eyelet terminal on the relay end of the fuse link
I was checking voltage at the fuses under the dash that are always hot. I was not aware there was a fusible link on the relay. I'll check that out tomorrow.
I cleaned the battery terminals and pulled the bulkhead connector contacts. Used sand paper and electronics cleaner in the bulkhead connectors. Seated everything back and nothing. I didn't check the voltages at the dash, but I was getting 12V at the alternator. When checking voltage at the post on the relay, it was 12V as long as the yellow cable was disconnected. With it connected, it was all over the place. I reseated the bulkhead connections again and got power. I guess I'll just have to see if I can reproduce the issue. Not really liking the idea of running around in the car waiting for it to happen troubleshoot on the side of the road.
I did ohm out the yellow cable on the relay and it does not appear to go to any of the bulkhead connectors. I'll have to check the schematic and see where it goes.
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The diagram says the yellow cable goes through the bulkhead and to the ignition switch. I'll have to pull that wire and see if it's broken at the blade connector.