The Stovebolt Site Forums The Shop Area The Electrical Bay Fuel gauge not workin

I have a new fuel gauge on a 1948 truck, new wire and new sending unit. I bench tested all of this before installing the gauge cluster and all worked fine. I marked the terminals at this time for ignition and sending unit. All is installed and now and the gauge sits on empty. I have about 7 gallons of gas in the tank. I checked and do have 12 volts to the gauge, the wire is good to the sending unit and I grounded the sending unit to the frame. I tried grounding the sending unit wire and gauge still did not move. What should I do next. As I recall the gauge itself needs to be grounded. The gauge lights work so I assume the gauge cluster is grounded. I have used search for a solution but am just getting confused now. I am trying not to have to remove the gauge cluster at this point. I just got it all together.

Check that your needles not pinched by the bezel. Sometimes the new repo gauges have a needle that sits higher than original.


Sounds like your cluster is grounded.
Sometimes we paint the inside of the gauge housing white. If you repainted yours you may have lost the ground for the fuel gauge.

I did paint mine white but I thought that I had bench tested it after that. I may be wrong on the series of how things happened. I think the first thing I will do is check to make sure the gauge itself is grounded. Looks like I might have to pull the cluster out after all.

Mine is doing the same. I just purchased a new gauge and wondered what the correct procedure on bench testing is performed?

Back of the new gauge has a metal plate the need to contact for ground

...pic...


This is the location where the new needle may be pinched
...pic...

heres how I bench tested mine
...video...

just make sure the sender and gauge is grounded.

you can also get some ohm resisters from radio shack
...30ohm test...

most problems with the new gauges is grounding
...pic...

and as mentioned before the height of the new needle
...pic...

I bench tested mine just like you show and as I recall I did have trouble with the needle touching. Thought I had that fixed, maybe not. Thanks for the info.

I removed the entire gauge cluster which also involved the speedometer and the electric wiper motor and tested the gauge again, works perfect. I am not sure what was wrong if anything. I think the main problem is the 30 ohm gauge and sending unit just do not give a real true reading. It is all back together now and I am getting the same reading as before, needle is just off empty with around 6 gallons of gas in a 16 gallon tank. If I remove the sensor wire from the sending unit the gauge goes over full, put it back on and will stop somewhere around 1/2 but then slowly drops even lower. If I power it at a later time with the gauge on empty I can really not see the needle move which is why I thought it was bad. I am going to fill the tank and see what happens. I did figure the one good way to partially test the gauge by removing the sender wire and see the needle move to past full.

You can ohm test your sender at the tank with your meter after you fill er up. should read around 30 ohm full
here a test with the sender removed but you can do the same test installed. ...pic...

check your ground at the sender
...pic... ...pic...

It is a pain to get the gauge out.Ive been able to get it out and in without having to remove my electric wiper or speedo to do it.

Let us know how it reads when full

Good luck

Hey Guys, hope its ok if I jump in. I have the same problem with my fuel gauge not working. I converted to 12 volts and have the original gauge. I installed a new stock wiring harness with a voltage reducer at the gauge as instructed. Should I get 12 volts when I test the wire going to the sender, or will it be 6? How can I test the gauge itself to make sure it works?