Fuel gauge-

Prob time to change out the Sending Unit.

 

use a flashlight and check your fuel visually by opening the tank,dont trust gauges.

 

You need to take it out of the tank. It's a long rod with a float on the end. You need to bend the rod down so it reads more. If you want to get it dead on accurate you need a special fuel stick to measure the fuel in there then keep adjusting the rod until it's correct.

Looks like this. Just bend that long rod (That didn't sound right)

 

Your fuel tank is in the wrong position.

check that the tank vent sits at the 12 o clock position. straight up.

I had the same problem on a 05 w900. kenworth rotated the tanks counter clockwise 2 inches. having the fill holes straight up is nice as you can put a few extra gallons in. but the sender won't read correctly.

 

You need to do what I posted above!

 

I used to figure out what I could run on full tanks (say 1,200 miles), then write my miles down when I topped off. Then I'd start looking for fuel around the 1,000 mile mark or sooner.

 

They sell those sticks in a lot of truck stops. I'm sure you could use something else. You also need to be on flat ground. Once you stop you need to sit for about 1/2 an hour and idle the truck. Most roads have a crest and more fuel ends up in the right tank. Sitting and idling will level out both tanks.

Doesn't matter how much fuel you have. Just do the math. In the picture above there are 5 screws that have to be removed. This job is real easy. Also, you can take the two wires off. Touch the two together and you fuel gauge should read full. Touch the positive to any ground and the gauge should read zero. Not sure which one is which but you can't blow up anything. That will verify that your dash gauge is working right.

It will probably take you anywhere from 3 to 5 times to get it right. Also!!!! When you bend the rod and ready to try you have to put all the screws back and screw it down. If you don't it will show a different reading with it screwed down as opposed to not screwed down.

I spent hours getting mine right on the money