Fuel gauge issues

[Mailboxperry]

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.

[MnTom]

Did the shop get the module back in correctly? If they didn't then the arm could be hitting the side of the tank. Did they drop the tank or lift the box?

[Mailboxperry]

They dropped the tank. Is it normal to have gauge stuck way below empty?

[Mailboxperry]

They said they double check that and tested it before they put the tank back on.

[dripley]

If they let the fuel basket turn when they tightened the locking collar, it could be hitting the side of the tank as MnTom said. It is very easy for the basket to turn when it is re installed. I might be a little suspect if it was working before the tank was installed and now is not. If they wont pull and check you might have to do it yourself and see how it is indexed.

[mulcher812]

You might want to check the body control module. It's located under the kick panel at your knees when sitting in the truck. Where your right knee would be. I would remove it and leave it unplugged for a while. This might reset the cluster receiver from the tank. 

[Mailboxperry]

The shop said they tried testing the new sending unit before reinstalling the tank. They ruled out anything wrong with the fuel tank and installed it back on truck. I will try the module thing. Thanks.

[Mailboxperry]

When you say leave the module out, do you mean drive with it out or leave key on with it out? And how long?

[mulcher812]

Don't try and drive with it out it because it controls several things in the truck. Do you have steering wheel radio controls? The BCM controls things like the radio controls, seat belts, mirrors and cruise control. I would unplug it and leave it out for approximately 20min cycle the key switch a few times then put it back together. Not real sure it will fix your issue but it may.

[Mailboxperry]

I will try thanks

[Mailboxperry]

We'll I unplugged what I think is the right module. I lost radio and door locks. After 25 mins still no fuel gauge. Where are some other places to look? Is it possible the PCM is the fault? Will try all ideas. Thanks

[MnTom]

Personally, I would lift the box to access the tank. Remove all the bolts except the rear most bolts (15mm socket) and three screws behind the fuel filler door. Then BLOCK the box up so it won't fall on you. Now you have access to the module. Unscrew the large plastic nut holding the module in. You can then move the float and watch the fuel gauge to see if it works. Then you install it making sure the float clears the side of the tank.

[mopartechnician]

You can take the connector loose and ground out or put 12 volts to the signal wire. That will tell you the wring and cluster are good

Also the sensor wire goes straight into the ecm. Its the dark blue/white wire

Edited May 21, 2014 by mopartechnician

[Mailboxperry]

Does it matter what wire I put 12v to?

[mopartechnician]

Yes needs to be signal wire. I cant remeber if its power or ground that will peg the gauge. Im thinking its power

[joecool911]

Jag has a write up on making an access door through the bed. That's on my mod list. Once done there is no more lifting bed or dropping the tank.

[Ilikeoldfords]

I know on a lot of the fords and GM's if you actually ground that signal wire it will peg the gauge. Havent tried it on the dodges before but I would maybe try grounding it first. lot easier to find ground then it is to get power back there.

[Mailboxperry]

Thanks for the info. I plan on lifting box this weekend. Until then, are there any relays or anything else like that I could check? Just want to plan ahead for this weekend while I tear apart the truck. Thanks.

[JAG1]

Jag has a write up on making an access door through the bed. That's on my mod list. Once done there is no more lifting bed or dropping the tank.

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

A volt meter set to OHMS, must have batteries disconnected, will show the sender is working when you move it up and down.

Edited May 22, 2014 by JAG1

[MnTom]

I would just leave the wires hooked up and turn the key on and watch the gauge when the float us moved.