Fuel sender unit testing

[irishcasey]

Hi,

I'd like to test a new fuel sending unit before re installing fuel tank and filing with gas. Wondering if I simply attach the green wire to the sending unit and then ground the black wire to the chassis with alligator clips and then turn the key to On if I can carefully move the sending unit arm and expect the fuel gauge to respond. Thanks !

 

[dogdad]

Basically yes, that should do it.

The actual wiper arm within the new sender (not the long arm attached to the float) is quite fragile, so take extra care to not bend or torque it when testing.

From my experience, I'd be more concerned that the gauge needle itself does/doesn't move predictably when you move the float arm up or down, rather than try to make it track to an exact amount of movement.

I went nuts trying to calibrate my boat-tank sender to accurately follow float movement til I finally pulled everything and put it on the test-bench and realized that it's not a very precise system. You essentially are being told you have "about" this much or that much fuel, and not that you have 1/2 tank or exactly 8.5 gallons (or whatever).

HTH.

 

[TR3driver]

From my experience, I'd be more concerned that the gauge needle itself does/doesn't move predictably when you move the float arm up or down, rather than try to make it track to an exact amount of movement.

In addition, the gauge takes a long time to fully respond. If you are actually trying to calibrate it, you need to wait several minutes (like 5 minutes) for it to actually stop moving after a change in resistance.