How To Bench Test a Fuel Sending Unit?

[Ironhorse]

I need to bench test an original fuel sending unit from a 1967 GMC with a 292 In-line six, not currently running. I have a multi-meter but unsure how to proceed with a test. How and where do you hook up the leads while in the Ohms position on the multi-meter? Any help is welcome, thanks.

[Big Kev-O]

Set the meter to ohms, clip the black lead to the metal housing (any clean metal) and clip the red lead to the screw/tab for the gauge wire on the top of the sending unit. The resistance should change from Zero ohms to 90 ohms when you move the float arm.

[HO455]

Here is how I did mine. Post 377.

https://67-72chevytrucks.com/vboard/...698377&page=16


And here is TBone1964's excellent thread on it.

https://67-72chevytrucks.com/vboard/...d.php?t=640615

[Ironhorse]

Originally Posted by Big Kev-O

Set the meter to ohms, clip the black lead to the metal housing (any clean metal) and clip the red lead to the screw/tab for the gauge wire on the top of the sending unit. The resistance should change from Zero ohms to 90 ohms when you move the float arm.

Yep, that's just the way I did it. No change in the ohm reading at all. Dug thru the parts stash and came up with another sending unit. Checked it in the same manner and the needle moved freely from near the 90 ohms mark to zero and in between with the float arm moved half way thru the range of movement allowed. Looks as if the first one is crapped, will keep the good brass float and the locking ring. Scrap the rest, thanks for the replies.