2nd Gen Non-Engine/Transmission Fuel gauge still does not work

[Hirt]

After over 2 years of using the odometer for a fuel gauge, I decided to get a new fuel level sending unit. Put the new sending unit in, and the fuel gauge still does not work. Dropped the tank again today and found that the sending unit is working correctly by measuring resistance right at the unit itself and where the wire harness plugs into at the top of the tank. Other then tracing wires all the way up the truck does anyone have any ideas? Seems like all the searches end with a new sending unit fixing the problem. Forgot to add its a 97 3500. Thanks in advance.

 

[Missouri Mule]

Check the resistance (ohmms) at the fuel gauge. Also you should be able to test all the gauges, but I don't remember how it is done. You mite try a search on that subject.

 

[Hirt]

I am only aware of a gauge check on 98.5 and newer. As for checking resistance at the gauge, not sure how you would do that. That is not how you measure resistance just how you would measure it there and once you did would you still expect the 20-200. I wouldn't think so

 

[Missouri Mule]

Fuel gauge testing. 1.turn key to on position. Disconnect then fuel pump module connector. The neddle should go to low end of gauge scale. If Ok go to step 2,if not go to step 4.
step 2. connect jumper wire between the sending unit ground circuit cavity and the fuel sensor signal cavity of fule pump module wiring connector.
the needle should move to high end of scale. If Ok replace faulty sending unit. If not Ok go to step 4.
Step 3 turn key to off position. disconnect adn isolate negative battery cable.Check for continuity between sending ground circuit cavity of fuel pump moduule connector and good ground. there should be continuity. If Ok go to dstep 4. If not ok g,repair open circuit to ground.
step 4. remove intstrument cluster bezel and cluster assembly.Disonnect the right cluster connector.
step 5. probe the fule level sensor signla circuit cavity of the right cluster connector. check for continuity to a good ground. there should bo no continuity. If Ok go to step 6. If not Ok repair short short circuit as required.
Step 6. check for continuity between fuel levle sensor signal cavity or right connector and fule pum module connector. there should be continuuity. If Ok repalce faulty gauge. If not ok repair the open circuit as required.

 

[Hirt]

I was working on it Saturday and found that after I put in the new sending unit, everything was good up to the harness behind the left front wheel well. After that connector is where the problem is, its just hard to track down after that. I will pull the instrument cluster out again and try what you suggested. Thanks for the info.

 

[GAmes]

I suggest you invest in a factory service manual. It contains troubleshooting procedures and will pay for itself many times over. I prefer the paper manual.

http://www.genosgarage.com/1997-DODGE-RAM-FACTORY-SERVICE-CD/productinfo/DFSM97_CD/#.U9GgkEBCzz4

http://www.genosgarage.com/1997-DOD...MANUAL/productinfo/DFSM97_PRINT/#.U9GhJkBCzz4

 

[Hirt]

I appreciate the replies. After being a member for several years now and being able to answer all questions from a search, I must say I expected a better answer then go out and buy a manual. I guess I was wondering if others experienced the same problem and maybe there was a common point of failure in a ground or possibly just some place in a wire harness. Missouri mule I appreciate the info you provided. Everything seems good with the gauge. Has to be in the wiring. I have plenty of wiring diagrams just need time to work on it. Thanks again.

 

[ARARAR]

Resistance is nothing more than an ohms reading looking into the unit across both leads and most units have an established electrical signature. Most instructions come with those specs. If you don't see anything you may just have a bad lead.