Ugh. Baffled by high alt stud voltage reading. Had a new alternator on the bench so i swapped that in. New battery because the old was not holding charge. All of my voltage readings are very similar to first numbers posted (15.6 at alt stud)

Tried a new regulator for kicks with no change. Figured it was worth a try...

Alt wire goes straight to starter relay (madd style) could it be something in that neighborhood? Fusible link connections?

Starting problem cured with new switch. Volt gauge still pulses 12-13 volts