mickey,
I guess I am not clear on the problem. Your truck/car is now 12 volts and you have a voltage reducer for the fuel gauge.
This setup worked in the past, but has failed now??
This is a new installation that you can't get working??
I think the proper wiring for the voltage reducer is 12 volts in on one end, and 6 volts out the other. Voltage would be read with a meter between either end and ground.
The stock fuel gauge should have only two terminals on the back, neither marked 12 volts!
A switched, fused, 12 volt source will go to one end of the voltage reducer, the 6 volt output will go to one side of the stock fuel gauge, and the other terminal on the gauge will go through the vehicle to the tank sending unit.
I don't know if this clears anything up or not.
Stuart
