No calibration....its a simple wiper POT that varies resistance to the gauge. With that said, however, the POT needs to be the same resistance range as the original to work with your gauge.

 

Just had the entire assembly replaced. The tank has been dropped twice this week, so it is not the float. I am positive it is in my cluster, but can not find any good forums for that repair. Please help!

 

In the FAQ here, you can find the factory service manual as a PDF download.

Download that, unzip the ZIP file, and do the troubleshooting steps that are in that.

RwP

 

Two suggestions if the diagnosis Raplh suggests does not work https://dodgeforum.com/forum/1st-gen...gas-gauge.html
And a TSB also haveing to do with the sending unit. IDk what year yours is but it applies to 91-94 dak http://dodgeram.info/tsb/1994/08-33-94.htm

Also this https://dodgeforum.com/forum/1st-gen...-friendly.html

You can lift the bed instead of dropping the tank. It's 8 bolts, disconnect the fill tube on one end of the rubber connector, unplugging a couple wires near the bumper, and the spare tire escutcheon.

 

Had a mechanic drop the tank and replace the entire assembly. I have the original manual and I know it is in the cluster. I need help working on the cluster itself.

 

Haha cluster. Truly a fitting description of that mess for people with my level of experience

 

Cluster's easy. Using the voltmeter, a) make sure that the gas gauge is getting power; b) check the resistance to ground of the sensor line. If b) is open, it's the wiring between the pump and the gauge; I personally would bet on that before I bet on the gauge. But that's what the testing's for.

RwP

 

Yeah what Ralph said....the cluster can't hardly go bad, but good spot to check your sender. There are two signals that come directly from the sending unit to the cluster. No pcm involved. It does go through the rear harness connector by the driver side fender and then the bulkhead connector into the cab. One signal is the ground signal to the empty lamp. One side of that lamp always has 12vdc from the cluster bus. The other side of lamp gets a ground from the sending unit when the contact on the bottom of the wiper is made. If the lamp is always on either your float i's stuck down or the wire is shorted to ground. As for the gauge the wiper in the fuel sending unit is a simple voltage divider using varying resistance. You should see a change in voltage at the gauge between 0 and 12vdc depending on the float position. You can measure the voltage or resistance with your meter to check.

 

If we are talking about my trailer light harness...That is cut and hanging down. Possibly where the issue is.

 

No, the rear harness connector (there's two) are the grey and black connectors near the fenderwell inside the engine bay on the drivers side. They snake down the fender then follow the frame back. They cover the harness for the rear lights, abs, and fuel pump and sender. The trailer harness you speak of is usually just spliced onto the rear lights and shouldn't affect the fuel sending unit.