Kevin,
I'm not seeing a fusible link in the schematic. The idea that you are only getting 0.8v, go back to the battery. First, confirm it is good. Make sure the terminals are clean and tight. Since you get that voltage at both the alt and starter, it sounds like a bad connection. If you look at the schematic (pic 1 above), note that power goes to the starter separately from the alternator. So the problem has to be back at the battery. Otherwise, you would still see 12v at the fuses and starter. Start at the beginning, the battery.
Let me know what you find.
Take care,
Joe
Sunday, February 28th, 2021 AT 7:31 PM