trying to get my sons fuel gauge to work, have tried 2 different sending units and have moved the float full swing and the gauge still reads below empty? I have checked with a voltage meter and it reads .25 volts, is that normal or should I be getting 12v? could it be a stuck gauge? thanks for any help, p.s. it is a standard gauge cluster.

Have you tried grounding the sending unit wire and then turning on the key to see if the gauge moves? When you do that don't let the gauge peg or you will burn it out. You should be getting a flashing power source using a test light. That is because the votage limiter in the dash turns off and on to create a 5v power source to keep from burning out the gauges. Do you have the sending unit grounded? There should be a strap that bridges the rubber hose from the metal fuel outlet tube on the sender to the metal fuel line. When testing the sender you need to ground it or it won't work. http://www.ebay.com/itm/Mopar-Gas-Fuel-T...=item27ea839a02

If you check the sender wire with a voltmeter you should be getting a pulsing 5v.

Does your temp gauge work?

If not, I suspect the Voltage Reg. on the back of the cluster.

I am using the grounding strap with the 2 that I tested and the temp gauge is not working. I will try the reg. from one of my parts cars. Thanks

I pulled the entire gauge cluster from my 74 satellite parts car and tried the voltage limiter, no luck. I tried a 9v battery to the leads of fuel gauge on parts car dash and gauge moved fine, tried it to dash on charger, nothing? looks like time to swap gauges

well, I think you got the fail. Need to consider if just one gauge doesn't work, never will be the limiter since limter works to feed all meters less the ammeter.

The deal is if your rallye cluster got the big opening gas and oil meters, is one piece gauge, so make sure your oil gauge works too on the donor car.