The ammeter is my 1966 Vette was not functioning, no movement at all, so I attempted to repair it.
1st - I verified voltage at both terminals that connent to the ammeter.
2nd - Measured the ammeter resistance for a possibe short - measured good.
3rd - removed ammeter - using a 1.5 Volt D size battery & flashlight bulb, I connect the new ammeter in series. The meter read > 10 amps. Ammeter appear to be working!
4th - To test the ammeter prior to re-installation, I used jumper wires & turned the key on & ran the fan. The ammeter does not move! I started the Vette & still no movement.
5th - Using a Voltmeter I verified >13 volts @ the battery w/ the alternator running.

What am I doing wrong?
Thanks in advance for helping!
Andy