My fuel gauge seems stuck at just above 3/4 full after a recent fill-up. Gauge has never been problematic before.

I haven't checked circuit breakers or gauge contacts yet, nor have I been able to get home to consult Streather's on any physical probable cause for the mis-read. Thought I'd just fire this out there and see if anyone else has seen something similar and happened upon a remedy.

Maybe this simply means I've achieved perpetual motion mechanics and am finally free from the tyranny of $4.50/gal gas ,

Matt

 

Matt,

I would want to isolate the problem. Is it the sender at the gas tank or is it the gauge itself? My new car's oil tank level gauge never worked. After consulting the wiring diagram, I discovered that the gauge is sending out power to the sender and it measures the resistance of the sender. To isolate the problem, I was able to break the connection on the sender and give it a ground signal. I saw the gauge move, thus confirming my fault was the sender.

I would do the same on your gas tank sender. My sense is your sender has failed. The 964 gauges are typically very reliable.

 

Rob,

Very logical approach; I'll make researching/checking the sender my first job when I get back to the garage. Thanks for the follow-up.

 

I disconnected the sender control unit and the gauge needle is dead; when I reconnect it, it rises to the faulty 3/4 full reading again, suggesting the sending unit is physically stuck OR the sender control circuit is flaking out.

I don't want to play "non-returnable parts" roulette on a $200 control unit; has anyone ever taken the white plastic sender body out of their fuel tank to visually inspect or even manipulate? Seems like the easiest way to prove the gauge/electrical part of this is or isn't the culprit. Trouble is, I can't see how to remove the body without a really big collar wrench or socket; it's like ~3" across.

 

Just get a new sending unit...

https://rennlist.com/forums/964-forum/225160-fuel-tank-level-sending-unit-disassembly-all-for-not.html

 

Thanks for digging that up; I guess I'm stuck with a $-only option, and you have the fuel-soaked gloves to prove it!

 

also, where'd you get your eventual replacement unit? I couldn't find the right part at Pelican and this listing doesn't look right, either.

 

For that car in that thread (a 91 C2 convertible) I bought a "used" one from Partsheaven for like $100 or so - they said if it didn't work right they'd send me a different one. I've always had good dealings with them.