Hi guys. I just got the issue with my key buzzer squared away and now it is time to get my gas gage issue fixed.

I checked most of the threads here but didn't find anything completely related to my problem. When I put about $20.00 of gas in the tank the needle goes all the way to the full mark. I have the console set up and the low fuel module is working fine. When I get to a certain point, when the gas is being used up, the needle will stay at the full mark but the low fuel indicator light will start flickering just lightly and then will come on steady when I know the fuel is getting low. The needle will go to about 1/8 to a 1/4 tank sometimes and then sometimes it just stays on the full mark and out of the blue when the fuel light is steady on then the needle will come off the full mark and go to empty.

Is there something I can check here to make this right or is it possible that the electrical part of the sending unit that works the needle is not working? Not even sure how to ask this...does the float action work both the low fuel module and the needle? Am I asking that right?

What needs to be checked first?

to tell you the truth i wouldnt even rack my brains trying to find this problem,,i had a similar problem i just ordered a new gauge and sending unit installed them and my problem was over

to tell you the truth i wouldnt even rack my brains trying to find this problem,,i had a similar problem i just ordered a new gauge and sending unit installed them and my problem was over

That's too easy. Plus I don't have the cash to just go out and buy a sender and gauge. It's a lot more fun to fix if possible.

I don't know about the low fuel module(disclaimer)
To test fuel gage disconnect the sender wire in the trunk, with the wire open to the gage it will read past full. Ground the wire to the gage and it will read below empty. If that checks out OK replace the sender, if not it could be wiring from back to front or the gage itself.

Jeff

I don't know about the low fuel module(disclaimer)
To test fuel gage disconnect the sender wire in the trunk, with the wire open to the gage it will read past full. Ground the wire to the gage and it will read below empty. If that checks out OK replace the sender, if not it could be wiring from back to front or the gage itself.

Jeff


Thanks Jeff I'll check it out. Of course this is with the ignition on correct?

Did the test at the rear wire harness. Unplugged gage, indicates full. Grounded wire to gage to ground and the gage indicates empty. I just need to check the body ground now. Gotta look at the AIM.
So far so good.

Do a search, the lead in the trunk should read between 0 and 90 Ohms depending on how full the tank is. It could very well be a bad sender or the float might be hanging up.

alan

Do a search, the lead in the trunk should read between 0 and 90 Ohms depending on how full the tank is. It could very well be a bad sender or the float might be hanging up.

alan

If I new for sure, and I really think it is the sender, then the tank has to come out. I gotta check the body ground first to see if there isn't a problem there I do believe I have most of the gas used up in it so I can drop it down.

On the sending unit. Is there any difference where I buy it? GM dealer, GM Parts Direct, Classic Industries, Ricks, Mexico? ANy thoughts here will help a lot. I only want to do this one time.

Well, use the ohm meter before you drop the tank. It could very well be a bad gauge. Verify you are getting the same ohm readings at the connector and up at the gauge.

alan

At a min, get a 0-100 ohm min rheostat, 1/2 watt or bigger, or two 50 ohm 1/2 watt resistors.

Dial in 100 ohms/two resistors in series and attach to ground and tan wire, gas gauge reads full.
Dial in 50 ohms/one resistor in series and attach to ground and tan wire, gas gauge reads half tank.
Dial in 25 ohms/two resistors in parallel and attach to ground and tan wire, gas gauge reads 1/4 tank.
These are approximate indications.

You might even have to remove the installed resistor from the back of the gauge.

At a min, get a 0-100 ohm min rheostat, 1/2 watt or bigger, or two 50 ohm 1/2 watt resistors.

Dial in 100 ohms/two resistors in series and attach to ground and tan wire, gas gauge reads full.
Dial in 50 ohms/one resistor in series and attach to ground and tan wire, gas gauge reads half tank.
Dial in 25 ohms/two resistors in parallel and attach to ground and tan wire, gas gauge reads 1/4 tank.
These are approximate indications.

You might even have to remove the installed resistor from the back of the gauge.

I wouldn't even know how to begin doing that. I am fairly mechanical but totally electronically iliterate. If it is spelled out for me, maybe.

What I did do though was check the gauge per above and then R & R'd the sender ground wire and at the moment it is working. It is on empty, and the low fuel indicator light is on steady. At first when I started the engine the fuel gauge was being very erratic, moving randomly between 1/4 and a 1/2 and back to 1/4 to full to empty and then it just settled down to empty where it should be. I am nearly out of gas so it should be right. Now I'll have to put more gas in to see what happens next. Crazy, man!!!