Amp Meter connections

The ammeter problems will not likely cause your starting problem, or the car would not run. Very little will operated if the ammeter circuit is open. No headlights, no dome lights, nothing. But the starter does not run through the ammeter. The only part of the starter circuit that runs through the ammeter, is the yellow "start" wire which engages the start relay. The relay is supplied power to it's contacts direct from the battery, and switches that battery power to the built in starter solenoid

Again, if the ammeter circuit is open, the car would not run.