Ammeter

[mejum]

I am trying to get my ammeter on my dash to work on my '57. It's the stock dash and ammeter, EZ wiring harness, 12v system.

I've got one 12v lead coming from the starter solenoid (12v constant) and I've got the other line coming from the fuse block that registers 12v when the key is turned on (alternator power).

When I turn the key to the 'on' position or start the truck, the ammeter gauge doesn't move from the D position (it's pegged below the D). I've tried switching the wires and it doesn't move either.

I've tested the ammeter with the multimeter and I am getting continuity so I believe the gauge/ammeter is good.

In theory, this is how the ammeter worked with the factory wiring. I've done some searching and I'm getting mixed results--some suggesting the ammeter works with the leads provided, others suggesting it won't work because of the higher voltage system.

What am I missing or overlooking?