fuel gauge not working

[C10]

Hi everybody i am working on a 1969 dodge 300 with a 440 and the fuel gauge reads empty all the time. I took the wire off the sender at the tank and when the key is in the run position i have no 12 volt power to it.So i took my power probe and put 12 volts to the wire and the gauge moved to half full.Any help on this would be great Thank You

 

[Ron H]

I had problems with my fuel and temp gauges not working on my Plymouth and took the dash out to expose the rear of the gauges cleaned up the connectors and ground wires retightened. I also had issues at the fuse block with deteriorated wiring and some cross circuitry going on with burned wiring. Not sure what your fuse block looks like; but on my '63 the block is tiny with the wires/connectors jammed in there tightly. After refurbishing the block wiring and the dash work, my gauges have been working fine for what it's worth here.

 

[Dibbons]

If your float has fuel inside it, the gas will register empty or partially empty. Just replaced my brass float a couple of weeks ago, it was completely full of gasoline and the gauge one day suddenly registered empty and then stayed on empty until I found the problem.

 

[Yatzee]

Hi everybody i am working on a 1969 dodge 300 with a 440 and the fuel gauge reads empty all the time. I took the wire off the sender at the tank and when the key is in the run position i have no 12 volt power to it.So i took my power probe and put 12 volts to the wire and the gauge moved to half full.Any help on this would be great Thank You

You should never apply 12 volts to the wire going to the gauge or the sending unit. You may well have fried it by doing this. The fuel level sending unit works off approximately 5 volts which is not constant but pulses every two seconds or so. Grounding the wire back at the sending unit should send the gauge needle to the full mark with the key on as there is a resistor mounted on the pickup/sending unit. Perhaps you've just created a whole lot of extra work for yourself by applying 12 volts - best get a manual.