When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Anyway, the fuel gauge does not work, and stays constantly in the "1/2 full" position. I was told the sender was bad, and indeed it was, the resistor was burned, which was confirmed by the reading I was seeing on my multimeter. I sent it to Jerry at GM Obsolete who seemingly did a nice job rebuilding the unit. I reinstalled the sender, and the gauge is still not working properly, acting exactly as it did before, showing the tank 1/2 full even though when I dropped the tank there was obviously only maybe a gallon of gas left in there.
There are two wires that go to the sender, a Yellow wire and a Grey wire. The poles on the sender are marked with a Y and a G, which I can only assume is Y for the Yellow wire and G for the Grey wire, even though these were reversed when I took the sender out. There was also a dedicated ground wire to the chassis also seen. I found that the yellow wire had a defective splice, but after fixing that the problem persisted.
Am I correct in assuming that the Y pole goes to the Yellow wire and G pole goes to the Grey wire? If so, where do these wire go to? What is the wiring situation in the back of the gauge? Would a cut wire or loose ground at the gauge cause this issue? I'm just so perplexed because in my experience when a sender or wire is bad or disconnected, the sender either goes full E or F, not sit at 1/2 full.
Also, what is the purpose of the second wire? Every fuel sender (that doesn't also have a fuel pump attached to it) I've ever seen has the wire that measures the resistance and that's it. Maybe a ground as well, but that's it. In this instance, is only one of the wires actually picking up the reading that gauge needs to read?
Some guidance would be appreciated. If I can't get this figured out, and if I still own this car this winter, I'll be figuring a way to put universal sender in the tank. Thanks all.
Wow man, thank you so much. That is great information, exactly what I was looking for. I've never seen that 12v to the fuel sender before, as I'm not familiar with early Corvette either. It really gives me food for thought, though. For those of us with this God-forsaken, 61 Olds sender that we can't find replacements for anywhere, would it be a better option to buy the Corvette sender, which is available new from several places (Corvettecentral.com has it listed for $70), remove the resistor and wiring, and transfer it onto the Olds sender. It should have the same ohm range of 0-90, and you could just cut and weld the float arm in the appropriate position.
Anyway, the fuel gauge does not work, and stays constantly in the "1/2 full" position. I was told the sender was bad, and indeed it was, the resistor was burned, which was confirmed by the reading I was seeing on my multimeter. I sent it to Jerry at GM Obsolete who seemingly did a nice job rebuilding the unit. I reinstalled the sender, and the gauge is still not working properly, acting exactly as it did before, showing the tank 1/2 full even though when I dropped the tank there was obviously only maybe a gallon of gas left in there.
There are two wires that go to the sender, a Yellow wire and a Grey wire. The poles on the sender are marked with a Y and a G, which I can only assume is Y for the Yellow wire and G for the Grey wire, even though these were reversed when I took the sender out. There was also a dedicated ground wire to the chassis also seen. I found that the yellow wire had a defective splice, but after fixing that the problem persisted.
Am I correct in assuming that the Y pole goes to the Yellow wire and G pole goes to the Grey wire? If so, where do these wire go to? What is the wiring situation in the back of the gauge? Would a cut wire or loose ground at the gauge cause this issue? I'm just so perplexed because in my experience when a sender or wire is bad or disconnected, the sender either goes full E or F, not sit at 1/2 full.
Also, what is the purpose of the second wire? Every fuel sender (that doesn't also have a fuel pump attached to it) I've ever seen has the wire that measures the resistance and that's it. Maybe a ground as well, but that's it. In this instance, is only one of the wires actually picking up the reading that gauge needs to read?
Some guidance would be appreciated. If I can't get this figured out, and if I still own this car this winter, I'll be figuring a way to put universal sender in the tank. Thanks all.
I have a similar situation with my '61 Fiesta wagon. The sending unit has been rebuilt and the gauge works properly down to about 1/2 tank but does not indicate below that level.
Bud, if your fuel sending unit has been rebuilt and it only registers accurately down to 1/2 tank, I'd call that good. You can always check the connections at your instrument cluster. Make sure they're secure and clean.
