Redfish
"Everything else is grounded at the panel"
Dana67dart
"except the ammeter"
Ron816
"I found no power at the fuse"
The ammeter is not fused (fusable link from ammeter to battery but nowhere does it run thru the fuse box) direct wire to alternator. No ground to an ammeter.
There is a tap off the black wire from the ammeter to the alternator that feeds some of the cir's in the car. One of the taps goes thru the fuse box.
