Gas Gauge

[80Grand_LeMans]

My gas gauge is stuck with the needle pointing to the right (past full). It still lights up but doesnt move. It looks like there is a new gas tank in there from someone before me. Is there a way I could fix this myself with limited tools and time or should I just have the shop drop the tank and figure it out for me.

 

[Toner283]

Usually when the needle goes over past full it is a bad ground that is at fault. The tanks (some) have a ground wire soldered to the top of the tank near the sending unit that grounds to the body near one of the rear gas tank strap mounts. The easy way to fix it is to drill a small hole in the edge of the tank (OUTSIDE of the roll weld or the tank will leak!) and run a ground wire from the tank edge to the body. The "correct" way is to drop the tank & reattach the ground in the stock location but this is a lot of work for the same result as the easy fix. With the tank properly grounded the gauge should return to normal. Hope this helps.

 

[80Grand_LeMans]

Could the wire be grounded anywhere? Or does it have to be grounded there...

 

[DOUG213XRJ]

This is what i would do .I would make up a jumper wire with aligator clips on both ends then clip one end on a clean body ground anyware and the other end clip on the gas tank .Make sure the contacts are good and clean.Then if the gauge works make and run a new ground wire.

 

[Toner283]

Could the wire be grounded anywhere? Or does it have to be grounded there...

As long as the tank is grounded to the body the gauge should work. Anywhere you are able to ground it is OK as long as it is a good ground.

 

[80Grand_LeMans]

Earlier today my car stalled on me (different topic). Anyway, after I got it running it seemed like my gas gauge was working... confused_swirl.gif

After I turned my car off, went to school, and came back out, it was back to its normal spot.

Any ideas about it now? Could the ground just be semi-bad and be getting good contact once in a while or something?

 

[Toner283]

yes, very much so. I had one that would change when I hit a bump.

 

[Killerdave8813]

Hey Guys,thought I'd throw in my 2 cents,seems to me that I used to test non functioning gas guages by grounding them to see if they'd do anything,good ground the guage would go to full,if it didn't the guage was bad,the fuel level sender is a potentiameter (big word I think I'm right) when the tank is empty there is little or no ground and when it's full it is a complete ground so I don't think Grand Lemans's problem is a lack of ground,I don't know for shure but I think our Pontiac cousins are wired the same way,I just went out to the garage and looked at my taillight harness and the red wire i believe is for the gas guage,look in your trunk on the drivers side and you should find a wiring harness coming over the wheel well toward the back,follow it toward the tail lights and you should find a plug,un plug it and then turn you ignition on and see what the gas guage does,if it goes to empty the guage and wiring to the back are good and you either have a bad sender or the wire after the plug going to the gas tank is pinched or bare and it shorting causing a full ground,if the guage stays at full either the guage is bad or the wire going from the plug to the dash is shorted somehow,Hope it helps! Good Luck,KillerDave

 

[80Grand_LeMans]

Thanks Dave, I like when you respond to my posts, haha. Ill check that out tomorrow, gonna do some work to the car.

Thanks to everyone else also.

 

[80Grand_LeMans]

I checked the harness like mentioned and nothing happened to the gauge. I took the dash off and took out the gauges and noticed a weird plastic-paper-like circuit board on the back of the 4 gauge cluster. Behind where the gas gauge is was 3 little metal pieces stuck into it. One of them was popping out a little so we pushed it back, put the gauges back and it worked.

Thanks for the help.