MEP-803A Fuel Gauge Pinned at about 95 Hours on the Clock

[Mweiss]

After much searching, I found a replacement part for the AUX fuel float. This has never worked right from day one. I remember ALWAYS hearing the AUX fuel pump run when I rotate the main switch through AUX. So this part never worked from the beginning.
A new one is quite expensive.

 

[rickf]

Have you pulled out the original one to see if it is nothing more that the magnets stuck to the pipe?

 

[Mweiss]

Not yet. I have to burn off the excess fuel so it doesn't spill. Right now, just opening the fuel filler results in diesel flowing out of the filler. Have to drain about a gallon first. But I plan to play with the adjustment a bit (try turning it and raise or lower it) in case it's hung up on something. Must be they installed it improperly and it never worked.

 

[Mweiss]

I've siphoned some fuel off, and am trying (without success) to remove the float switch. I watched Colt's video on how to remove it, but it's not going. It' supposed to slide up 5" and then rotate clockwise, tilt to the right and rotate as being pulled out, but it's stopping at 1/4" of lift. Something's hitting the top of the tank. I can only rotate about 30°, but no matter which orientation, it's blocked from coming out by something hitting the tank ceiling. I can see it bend upward when I pull on the switch. It should come right out. Maybe somethings' seriously deformed when they assembled mine?

 

[Mweiss]

Finally got the float switch out of the tank.

What I found was quite shocking: some type of GLUE had dripped on the upper float prior to assembly, freezing the float in the lower position permanently.

I was able to break it free with considerable force. Then I scraped off the glue, oiled the shaft and made sure the float moved up and down smoothly. Then I verified with an ohmmeter. Float down, black wires open. Float up, black wires shorted. Checked the bottom float too. Up, shorted, down, open. Satisfied that it worked, I reassembled it.

At first I heard a fuel pump running, and thought "now what?" but I looked at the bubble in the tygon tubing from the aux tank and it was not moving. I felt the aux pump and it was not vibrating, so I realized I was hearing the main pump. And no change in sound when switching from aux to main (until now, I'd hear both pumps running in aux and the sound would change when switched to run position.

So the aux pump should work when needed.

I just have to buy a new fuel gauge as that appears to be non functional despite good resistance readings from the sender.