I recently put a new fuel pump on my truck. The gas gauge in the truck is showing full when I know there is hardly any gas in the tank. All my connections are hooked up and the ground strap is secure. The truck is running fine so everything is working properly but the gauge.I checked the float and it is not hung up in the tank. Any tips on why or what to check on the truck to get the guage working properly? Thanks for your help

 

I guess I would first start by back probing the output from the sender to see what kind of voltage it is putting out. If the voltage changes when you jump on the back of the truck (sloshing fuel - changing level), then it is possible that the gauge in the cluster is bad or just stuck.

 

well here's the thing. i had a buddy post my first comment, so of course he left some stuff out. the gauge worked properlybefore i put my 3rd fuel pump in. im gonna check the elec. stuff out tonite, but like i said up there, i cleaned the ground up, hoping that would be an easy fix. but no luck. so could a wire maybe come out of the connector? we'll see. but other than that, i dont believe the sending unit is bad. and if the gauge is stuck, how do you get it un-stuck?

 

Depends on what is doing the "sticking". If it is something wrong with the wiring, you will have to find and fix the fault. If it is a problem with the small little stepper motor in the cluster, then the only resort may be to find a replacement cluster.

Based on the updated info you provided, my bet would be on something at fault on top of the tank. If I remember tonight I will see if I can come up with some connector views and wiring diagrams for your sender/pump.

 

I too am having this problem with my '93's digital fuel gauge. [:@]
I did read on another forum that:

"A poor ground for the fuel level sending unit will produce the same symptoms, (dancing needle). A poor ground will increase resistance and shorten the life of the fuel pump also. The fuel pump and fuel level sending unit are grounded at the same point on the vehicle. The ground on a 4 door is on the rear crossmember. The ground on a 2 door is at the frame rail very close to the filler neck. Remove the bolt and clean the terminal and the frame with sandpaper, a wire brush, or a file until bare metal is visible."

Hope this helps you. I have not looked at mine as of yet.

I hope swartlkk does come up with the connector views and wiring diagrams for the sender/pump.

 

so did yours ever ended up workin or is it still doing it? i did already sand and wire brush and used some rust remover and made sure the terminal was good, which of course in my luck none of these simple things fixed my prob. so im just guessing that its gonna hafta be a bad sending unit. how in the matter of carefully changing my fuel pump it happened, but by now im a tank removing expert and im just gonna hafta take another chance with money i dont have and change the sending unit. really startin to frustrate me. but another quick question, on a13 gal. tank how many miles roughly should it get you when its full?