[Richard]

While fixing the broken fuel pickup tube as chronicled in the Emergency section, I am replacing the fuel sender. Easy to do while the tank is out of the coach. I had previously replaced the sender about 2 years ago but it never read correctly, always reading lower than what was actually in the tank. I assumed that I bought the wrong sender or the wrong length sender. 

So I bought not one but two more. One from VDO and one from KUS because I liked the external bobber on the sender. 

Installed both the them and same result. The tank reads much lower below 3/4 tank than it is. I could prove this because I still had the senders external to the tank. I suspected a wiring issue, so I wired the sender directly to the gauge in the cockpit. Same result. 

I suspected faulty ground, so I made a new ground. Same result. 

Hmm, order a new gauge. 

Then I pulled the old gauge out, and discovered a mysterious screw hole on the side of the gauge. Bingo, I wired it all up on the bench with the KUS sender, and was able to adjust the gauge to read very close the actual level of the float. Woo Hoo, who knew. The variable ohm lettering on the side was a clue that the gauge may be adjustable. 

So, if your gauge is off, it’s something to look into.

Hmmm, cancel order for new gauge.