how do i troubleshoot an inop gas gauge?

[nrt69]

is there an easy way to test the gas gauge to see if the gauge is bad or if theres something wrong at the tank i need to fix?

[tan top]

take the fuel sender wire off &  ground it  ,  gauge will peg full or past off scale , if gauge is working !    next look at sender , make sure the sender is grounded  , not the tank because the sender is insulated via the rubber gasket!

[Patronus]

 

usually its the ground

[nrt69]

just now getting around to this...

i turned the key on and and ran a wire from the blue wire (the gauge wire, on the sending unit near the fuel line) to the frame and the gas gauge didnt move. did i do that right?
also, my owners manual says somehting about the ground strap but i dont see one anywhere. is there suppsoed to be another ground wire somewhere on the tank? if so, where?

[Plumcrazy]

i turned the key on and and ran a wire from the blue wire (the gauge wire, on the sending unit near the fuel line) to the frame and the gas gauge didnt move. did i do that right?

That's the right way to do it but just to be sure try running a longer wire back to the negative battery terminal.

[nrt69]

run a wire from the sending unit to the negative batt terminal???

[y3chargerrt]

Yes

[W4ATL]

But if it goes full scale don't leave it hooked up for long.

[nrt69]

hopefully i have a wire that long.

and just to clarify: i do or dont need to ground the sending unit to something? it wasnt clear to me from reading above. the only wire i see is the gauge wire connected to the sending unit. is there supposed to be another ground wire somewhere else?

[W4ATL]

It should ground through the car frame so no need for a ground.

[gtx6970]

Unhook the sender wire and with a test light, ck it (key on) you should see a pulse in the light. If you do, gound this same wire and the gauge should go all the way up past the full mark.

[Bsrob]

I am really late replying you may have fixed your problem by now but if your gauge is always reading EMPTY then take sending unit out completely and make sure your float didn't sink. If it did there is a small hole somewhere and you can solder it up. Just make sure you let it drain first . that was the case with mine. It had a hole in it and sunk. I just ordered a new one here recently.

[cactuswren]

just now getting around to this...

,my owners manual says somehting about the ground strap but i dont see one anywhere. is there suppsoed to be another ground wire somewhere on the tank? if so, where?

The ground strap is about a 5" strip of metal with a clip on each end. One end clips on the metal fuel line and the other clips on the sending unit.  Otherwise the sending unit won't be grounded due to the rubber gasket insulating it from the fuel tank, and short rubber hose that attaches the sending unit to the metal fuel line.