89 7.3 fuel problems

[dadelmatto]

I have an 1989 f250 7.3 idi and my fuel gauge doesn’t work it reads full all the time until the tank gets down to about a quarter then the gauge starts to move back and forth when the diesel in the tank moves. It’s in the front tank and I was wondering if the sender units are interchangeable through gassers and diesels can anyone help me out?

[1stgen3rdgendodge]

Have you messed with the sending unit at all?? I know in my dodge something got bent in the unit cause I'll run it till the gauge says half a tank and then I'll fill up and put around 27 gallons in it and it only holds around 32. It's takes forever for it to drop off of full too. I can run it for around 120 miles before the needle starts to move. Not sure if the gasser and diesel units are interchanagble. Kinda new to the ford diesel scene.

[dadelmatto]

no i havent messed with it at all i bought the truck like that. i think its a bad sending unit but ive only found one replacment and it comes with the pump and its right around 400 dollars and thats pretty tight for my wallet.