quick fuel gauge question. m38

joebuck · Post by **joebuck** » Wed Sep 25, 2013 5:52 pm

When I hook new sending unit up .it goes from to full to empty. Unhooked it shows full. what am i missing?

Post by **wesk** » Wed Sep 25, 2013 9:16 pm

Read the Army TB for the instrument systems and the light will appear at the end of the tunnel!

The TB is available free in PDF format right here on our web site's Downloads Page:
http://www.willysmjeeps.com/v2/modules. ... tit&lid=46

joebuck · Post by **joebuck** » Fri Oct 18, 2013 3:51 pm

I read the download and tried those tips to no avail. I am also almost ignorant with an ohn meter but think i understand it now...

heres what happens with Circuit light.....when i unplug the wires from the gauge that attach to base of sendinging unit and touch gauge wires unhooked with light testor...it burns!!!

when i hook up gauge wires to sending unit and touch light tester to that contact....NO light.

Does my sending unit need to be ground? if so how? thanks for any help

Post by **wesk** » Fri Oct 18, 2013 7:25 pm

If you cannot sort out the tests in the TB and properly decipher the ohm meter and the test results then all the second guessing over the phone or the web will not do you much good. Before you burn up a wire or two or damage an indicator get someone local with the aptitude to perform the tests and interpret the results and have him show you how to do it.

joebuck · Post by **joebuck** » Sun Oct 20, 2013 7:07 pm

After running some additional test I pulled sending unit out. The float was full of gas. So basically it sat on bottom of tank rightfully showing empty. hooked up sending unit out of tank and hooked up a ground and rotated float arm up and down and low and behold.........it WORKED

So no all I have to do is replace the float or fix it....wonder if I can use something else instead o f that brass float?

Post by **wesk** » Sun Oct 20, 2013 7:28 pm

Drill 2 holes in the brass float. Drain it. Then apply a 1 or 2 lbs of air pressure to it and submerge it in water and mark the leaks. Then solder or braze the leaks and two holes.

joebuck · Post by **joebuck** » Mon Oct 21, 2013 3:06 pm

winner winner chicken dinner....thanks as always Wesk

joebuck · Post by **joebuck** » Wed Oct 23, 2013 7:05 am

Additionally sending unit was not grounded properly to tank becasue of an OVER large homemade gasket. Retrimmed and got grounded properly.