Technical 1937 Dodge gas gauge.

Just got my gauges back and trying to get the fuel gauge working. I did switch the truck to 12 volts. I only have 2 hook ups one red one green, and can't get anything to happen. I do have a aftermarket gauge in there now that works fine, but would like the original. What can I do?

 

I'd be asking the guy that did your gauges.

 

I already sent him a message, before I asked here. It always good to get other ideas. I believe Dodge in 1937 was a positive ground.