Ike,
The power path is from the starter solenoid through the circuit breaker nearby. It then goes directly to the ammeter.
From the ammeter, power goes back to the top two fuses on the passenger's-side fuse box. There should be a jumper between the top two fuses. I have forgotten this jumper once before (not bad for 600+ harnesses...) so check the voltage at the #2 fuse first.
The power then goes back through the F-G junction (large brown and white wires) to the ignition switch.
So...
Check voltage at each point, in the sequence I've described. It's probably something very simple.
