I installed a new fuel gauge in my 66 dodge dart. I used the one wire from the sender unit as the signal wire for the gauge, but this does not include the voltage regulator that is in the stock gauge cluster. WHen i turned the car on the fuel level went right to full and i know the tank is not full. Could this be becuase that voltage regulator is not install? ANy ideas to fix it. THe gauge is for the right inpedence levels. PLease help.

i should mention that the gauge i am using is an autometer phantom gas gauge with an impedence of 73 ohm empty and 8-12 full. To me this should work fine and be reading the correct level but i think the impendence is being thrown off by the limitor\regulator circuit. Does this seem correct?

The resistance range is right; all aftermarket gauges have internal regulation and should NOT be connected to the voltage limiter; they should be connected to full +12V. If you have a bad ground at the gauge or a shorted wire to the sender, or a shorted sender, you'd get those symptoms.

An inexpensive 12V testlight (the type that use a small lightbulb, are about the size of a large pencil and come to a point) should make the gauge read something like 1/4 to 1/2 full or so - that lets you test the circuit if you disconnect the wire to the sender right at the tank.

Thanks for the info, but all the problem was fixed when i checked the wiring and found that the ground wire was connected to the signal post. The signal wire was connected to the ground post so the gauge was grounding out and thats why i was getting a reading of over full.

Its all good now though. Everything works!!!