'92 fuel guage

[kodiak2]

I replaced the tank sending in my diesel due to erroneous readings on the guage. Now, as before, the guage works from full to 1/2 and then drops down to empty. I replaced the guage, and the same problem continues. Oddly, with the ignition off and after sitting for awhile, the guage seems to give a accurate reading ( when the tank is less than 1/2 full)
This has me stumped and was wondering if anyone has run into and cured this problem?

[Gordon Maney]

If the performance of the gauge changes after the truck sits for a while that suggests that a temperature change is causing this difference.

You should be able to assume that both of your new parts are good, even though we can't know that for sure.

I find myself thinking about ground circuits. You need to identify the main ground circuit attachment points and clean them. This may seem rather lame to you, but I urge you to do so.

[kodiak2]

Thanks Gordon, as usual you are the light appearing at the end of my diagnostic tunnel!

[kodiak2]

Gordon,
Just to let you know, I traced the wiring from the tank and found a ground behind the engine on the firewall. I cleaned the ground as well as the battery to engine ground. The fuel guage is now working and showing 1/4 tank. Hopefully, this will continue through the next tankful! Anyway, your theory is working and I will let you know if anything changes. Thanks again!

[Gordon Maney]

Great!

[kodiak2]

Fuel sending unit

Hi Gordon,
My fuel guage worked for one tankful, then totally died. One of the parts must be bad or another problem in the wiring. At the ripe age of 65, I'm starting to believe in automotive gremlins. A friend gave me a sympathy card after all the trouble I've been through, but he did this when I got married too.