Fuel tank ground or lack thereof

As you know by now, the deuce fuel tank has one single ground connection from the frame, wire #79. It goes to the fuel pump connector, that's it. From there the grounding of the rest of the tank and level sending unit must rely on the mounting screws.

Working on the fuel tank for my xm757 I realized that the wiring harness to the tank has no less than three separate ground wires, one to the pump connector, one to the level sending unit and one to the tank itself. Guess the grounding problem of the tank was recognized during the sixties, but nothing was done to improve it on the deuce.

Bottom line, check your fuel tank ground(s).

Just another think for us to envy about your 8x8, and to learn from for our rides...

One of the "fixes" that gets posted often on the M37 and M38 forums for faulty fuel guages is to establish a new ground line for the tank sender by sliding a new lead under one of the mouting screws.

Re: RE: Fuel tank ground or lack thereof

CGarbee said:

Just another think for us to envy about your 8x8, and to learn from for our rides...

Click to expand...

No need to envy, there are a few out there that need to be saved from the scrapper or from being shipped to South America.

PS. The fuel tank in the image above is from an M52, it's not the original 80 gal aluminum tank.

Bjorn,
Speaking of gounding, great informative article in the latest Military Vehicles Mag. Hat's off.

As you know by now, the deuce fuel tank has one single ground connection from the frame, wire #79. It goes to the fuel pump connector, that's it.

Click to expand...

I've got a "tab" of some sort under one of the three nuts that hold the (fuse block) cover down on the in-tank pump. It has a "terminal" look to it, but I'm not sure. Any idea what this might be? Is this where a ground goes? I've got 24v at the two-wire connector going to the pump.

Also, in an effort to troubleshoot my in-tank pump problems, after pulling the pump, I see where the ten screws that secure the pump, all had sealant on the threads. I understand this keeps fuel from seeping/bleeding out. Does this affect the ground return? I was thinking about using internal/external combination toothed lock washers to make the grip (connection), but that'll create a problem with seepage. The three nuts on the pump's fuse block cover had the star washers. Is that all that is required? My new in-tank pump has split lock washers. (...and wouldn't you know, metric threads/nuts).