Using Old Ammeter

Yea I saw those a while back and the sunpro conversion looks like a winner.

I was just thinking since the only load running through the car would be what was in the car I may be able to use the stock ammeter. I even ditched the lighting load and am installing relays vs direct power through the light switch.
The load that the black wire carries would be far less than 30-amps with my modifications.

The ammeter would be hooked up as before its just the black (ammeter) wire would be fed from the battery as opposed to being fed from the alternator.