I just bought a 2002 dodge 2500 cummins quad cab. The fuel gauge was not working. It was stuck below E with fuel light on. Took it to local shop and they said need new sender. Looked on here and found the correct part number. Thank you. Shop installed and gauge still not working. Shop tested wires and said they are sending signal all the way to the PCM. After that they don't know. I looked on here how to test cluster with the trip button. The gauge moved as it should. I brought truck home and need to know where to look next. Thank you.

I'm also assuming the other wire should be the power. If so how much power should be there?

Edited May 25, 201410 yr by Mailboxperry

Its 5 volt if i remember right and I do belive the gauge should move just like it did

I don't think I have power there. Where could I find 5v on the truck to run a jumper wire to test it?

12 volts will be fine for a test. Now if you dont have the 5 volt supply than you need to find where its bad. I will look at wiring diagram when I get a chance

I

I was wrong there are only two wires used. A ground and a signal wire

Connector 129 is behind the drivers front wheel well.

Connector 130 is at the fuse box

Edited May 25, 201410 yr by mopartechnician

Bare with me here, so the non signal wire is a ground? Does that mean I just need to ground it and all should be good? Sorry I'm not the best with electrical but I will get it sooner or later.

Edited May 25, 201410 yr by Mailboxperry

You need to ohm the ground wire at the connector to ground. You already know your signal wire works since you grounded it out and the gauge moved

And the black wire is ground

Edited May 25, 201410 yr by mopartechnician

So I was looking at the PCM and noticed its ground was pretty dirty. So to be cautious I unhooked the batteries before I removed the ground cable. Took it off and cleaned the ends. Hooked everything back up and now my fuel gauge is stuck on full. What did I do wrong or what does that mean?

It means maybe your fuel tank is full? How much fuel do you think it has in it?

Lol. It's not full. I have about 150 miles on the tank.

That still may be full according to the gauge. Give it some time and see what happens.

Thanks for your help.

Thanks for your help.

You are certainly welcome, sir!

We'll it was short lived. Didn't even make it out of driveway and back to empty. Is it safe to say the PCM is to blame? All the wires are good. It also looks like the PCM has been replaced recently. It's the cleanest part under the hood and it's appears to be a Motorola brand.

Double

Edited May 26, 201410 yr by mopartechnician

Fuel gauge runs through the ecm on a diesel. Runs to the pcm on a gasser. I will find where it said that i dont understand why its this way

This gauge is controlled by the instrument cluster circuit board based upon cluster programming and electronic messages received by the cluster from the Powertrain Control Module (PCM) on vehicles equipped with a gasoline engine, or from the Engine Control Module (ECM) on vehicles equipped with a diesel engine over the Programmable

I am confused. I followed both wire from the sending unit and they go into the PCM. We'll I think it's the PCM, it's on the passenger side on the fire wall behind the air filter. Does it go to the ECM after the PCM?

Thats what I don't understand, ecm controls all engine control stuff. The Pcm (on the firewall) controls everything else. But, the service manual states different, and I can only find the one wiring diagram with the wires running to the pcm. I would ohm out both wires and see what you get.

Need to do a write up on this along with a material and bolts list.

Yeah, I know you've offered to give me the material list, but would be cool if everyone had the info.