Pulled the power supply to the sender from the gauge and measured the voltage. It was 8 volts.
Pulled the ground wire from the sender off at the ground post on the frame, put a voltmeter in series to the ground and got no volts.
Sounds like the sender is pooched.
Not looking forward to changing that.
I changed the gas filter and could see the filter element looked gummy.
Has anyone else had a problem with certain brands of gas ruining the senders? I remember Shell in Canada having to pay to replace ruined senders because they had a problem at the refinery that produced fuel that left gummy deposits.
If this is the case, is there an additive I could try that might clean things up, rather than replace it?
I haven't experienced this problem and I just buy cheap gas. I had a rusty gas tank that I had to replace a few years ago and, when I had the tank out, I noticed that my sender was rusty but still in good working order. Since the tank was new, I replaced the sender too.
My guess is that that the wiper on the float arm wore out the resistance windings in the sender.
You will only read OHMS coming from the senderNot sure what sender you have but a lot of older ford stuff reduced the dash cluster to 6 volt up to the 60s ? some time . I know if you disconnect the sender wire on a older gm the gauge will read full . but it depends on what you have . Is the float varnished cork ? I could see ethanol screwing that up?
You're almost correct on the Ford cluster, Slim. The 56 Fords were an oddball, cuz they went to 12 volts, but dropped back down to 6 volts again in 57.
__________________
If brains were wire, some couldn't short circuit a firefly.