Hows it going guys. Im stumped. Even my 1986 GM Service Manuel isnt too specific from the issue that Im having. Ok. Here we go. I installed a new FP, strainer, fuel filter, and sending unit. I have verified that my fuel gauge and instrument cluster work. I verified that the both ends of the contacts on the cluster and the the connectors are free of corrosion. SO, once I filled up my tank, my gauge read that Im at 1/4 tank. I was confused that since i had a new sender it would read 1/4. So I bought a new sender, measured the resistance with my Fluke 110 Plus multi-meter and verified 0-90 ohms on the sweep. I raised the rear of my IROC and disconnected the FP harness at the wall/connector and plugged in the new sender (hanging at the differential). Switched the key to on and checked the gauge. It read empty. So I went under the Camaro and flipped the floater the other way and looked at the gauge. It moved from E to 1/4. So that said, the current sending unit in the tank is perfectly fine. I read that the floater can get "stuck" against the baffle. But given that the existing and the new sender both have the same results, clearly the floater is not stuck inside the tank. Has anyone ever had this issue? I can live with having the tank topped off all the time. But I cant stand to see the tank

at 1/4 all the time either. I dont want to add another gauge pod to the A piller. Can it be that the "Pink" wire is bad?

 

​​​​​The fuel gauge has two ground paths. One ground is through the gauge GROUND terminal and goes through the dash ground circuits. Other ground path is through the gauge SENDER terminal and goes through the in-tank fuel sender.. The in-tank sender essentially diverts current away from the gauge GROUND terminal; and the more current it diverts (lower resistance in sender), the more the gauge needle is pulled towards empty.

Basically not enough current is going through the gauge GROUND terminal causing your needle to stay low. There's too much resistance in that GROUND terminal circuit. That circuit has a screw at the gauge that connects to the green screen, that connects to the connector that touches the green screen, that connects to a wire that grounds to the metal part of the dash, that bolts to the body of the car. If any of that has a poor connection or high resistance then it's going to throw off your gauge reading.

I don't know if I explained that in a way that is understandable?

 

Yeah man. It makes sense. Basically I need to check my grounds. All terminals on the gauge, 3 chromed anchors which contact the printed circuitboard, and the terminals at both ends of the instrument cluster are good. One area that I can't find is the ground at the rear of the Camaro. Some say the front of the hump, behind the driver's seat, and hatch area. As for the ground on the dash, that's a new one for me.

 

Dash ground wires screw into the metal dash structure next to steering column on my Firebird. 2 or 3 wires, I can't remember.

Those green screens need cleaning now and then. The "spring" terminal in the connectors that plug into the dash is a goofy idea at best. Touch up the screen and "spring" terminals with a pencil eraser. My car needed a little cleaning after about 25 years or so and then all the dash electrical came to life again.

I don't want to discount your gauge being bad, but I'd check ground path first.

 

Ah man. Dude I've confirmed that my gauge works. I've hardwired the extra sending unit to verify it's function. It works just fine. All the copper contacts under the spring loaded contacts, I actually sweated then with solder after buffing them out and soldered the contacts to the base solder on the printed circuitboard. So it's gotta be a wire or connection.