'72 C-10 Gas Gauge

[C10 - C90 Bill]

The Gas Gauge on my '72 C-10 used to always stay pretty steady, but lately it is fluctuating for some reason. It can bounce back and forth from 1/2 to 1/4 in the matter of seconds. Trying to figure out what is going on. Do the tanks have baffles in them? Unless it's some kind of electrical problem. Let me know what y'all think.

Thanks

[Steeveedee]

Don't know if they have baffles, but I expect that they may. I'd be checking the electrical connections, personally. If you don't have service and repair manuals, you can download them for free, here- manuals for maintenance and for overhaul are available. Be sure to get both.

https://67-72chevytrucks.com/vboard/...ghlight=hatzie

[LockDoc]

-
The stock '67 - '72 tanks do not have any baffles in them.

[Sheepdip]

More than likely the sending unit is starting to go. It's ez to pull and test it.

[LockDoc]

-
The easiest thing to start with is the wire from the tank to the Fuse panel. It is a Tan wire and lays under the door sill plate. It is subject to chafing and the elements. Unhook this wire from the tank sending unit and the fuse panel and test for continuity and grounding. Post #5 in this thread shows the fuse and circuit layout for one of the fuse panels. The wire you are looking for is plugged into the one marked "Return from fuel level sensor" and will be marked "Fuel Ga."

https://67-72chevytrucks.com/vboard/...d.php?t=741245
.