Fuel gauge stuck on full

[DanMcG]

There is a rubber ring between the sending unit and the tank body, so the sending unit should be electrically isolated from ground.

I was thinking that since it was screwed to the tank it might be a common
ground, but you could be right, the ground on the sending unit might be isolated.

I might dig out my new unit and test it out

 

[1985c20]

The sending unit will get a ground through the tank if it has to. The tabs the lock ring slide into is on the tank so even with the o-ring it’s still directly touching the tank. Trust me I just found last weekend that we ripped my ground wire off putting the bed on my k20 and that is still getting a good enough ground for the fuel gauge and tbi fuel pump to work. It runs and drives fine I only found it messing with the filler neck.

 

[thecantaloupeman]

The gauge stays where it last was when the key is turned off in my truck. It does not fall to E.

Look at your bulkhead connector at the firewall. There are 3 ‘plugs’. The largest one closest to the center of the vehicle has a pink wire at the bottom—pink 30. Make sure it’s in good shape from there back to the tank sender—where the fuel lines and wires connect to the tank. You should be able to see it in the gap between the cab and bed.

The ground may be between the tank and frame rather than on top of the frame. Look for bolt threads inside the frame rail for reference.

I looked at my bulkhead like you said and I've noticed these crappy looking wires from the start but maybe they are related to my gauge? Would any of these wires have anything to do with it? I didn't see a pink one but maybe it's just because they are covered with dust. I looked underneath the tank inside the frame rail and it looked like there was an orange wire that came down from the tank. I jiggled that and nothing happened. That couldn't be the ground wire right? It looked to be in good shape.

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

You must be registered for see images attach

Sent from my SM-G950U using Tapatalk

 

[Dave 84]

The wires in pic 1 look a little burnt but hard to make out but a volt meter will help you alot not sure if you have 2 tanks or not but check this out find the wire that goes straight to the tank with it plugged in back probe or pierce( if you live were it snows make sure to re seal the wire) and see what ohms it has if it reads some were between 0-90 then keep tracing it forward till you lose your connection and that's your place of interest sorry if this is confusing let me know I will try my best to simplify it everyone is different!

 

[Frankenchevy]

@thecantaloupeman

The pink wire should be at the bottom of the highlighted connector.

You must be registered for see images attach