Hello
Can anyone tell me how to test a fuel sending unit that is out of the truck sitting on my workbench. Any help greatly appreciated.
Luke

 

A fuel sending unit is a rheostat (variable resistor, also called a potentiometer). As the float moves up and down, the resistance changes. Clip a multimeter to each of the leads on the top of the sending unit. Hold the sending unit upright, and let the float drop. Your meter should read 70 ohms. As you move the float upward, you should see the resistance drop. Once the float is in the highest position, your meter should read 10 ohms.

Also make sure that the float actually floats - the float is made out of two halves of brass that are soldered together. The most common problem is that the solder ruptures and gas seeps into the float, and the float sinks to the bottom of the tank. This makes the fuel gauge read empty permanently.

 

Perfect timing for your answer. I remembered reading this the other day and when I pulled the sending unit in my tank tonight there was fuel in the float.

Any way to fix this? I would think a new float is the only way, but I'm not sure they sell them separately - do they?

 

I wanna thank you for the info. mine is good.

 

The float is indeed sold separately. I happen to have the LMC catalog open right now, but I'm pretty sure I've seen them in Mac's, JBG, etc. I think I remember Ford still selling them too.

 

COAZ9202B .. Fuel Sending Unit Float / Available from Ford

Fits ALL 1957/79 Passenger Cars / Trucks / Bronco's & Econolines.

MSRP: $13.17 // FTE Ford Dealer Parts Dept sponsor PARTSGUYED.COM price: $9.48.

This is...at least...the 400th time I typed this float's Ford part number, applications, and prices here on FTE.

 

And I'm sure you'll post it a few more times after this too...

I hadn't put any effort into searching for the part yet since I'm not even close to putting the tank back in.

Thanks for posting the info again though - saves me from actually have to do a search when I get around to going to buy the part