Recently re-married the ex, inherited this 89 F250 which seems to not selecting the rear tank. The gas guage does not move when selector switch is switched between front and rear. 10 amp fuse was missing (replaced no help) and seems to be stuck on front tank. Fuse location is marked (fuel selector). I'm a retired electronics tech wih moderate mechanical experianc and I am not one to just start yanking stuff out. Also has issue with dash lights and blinkers. If anyone has a link to the wire diagrams?

 

The selector switch changes the tanks and the dash fuel gauge from one tank to the other.

The switch is far more reliable than the selector valve.

 

I was thinking the selector switch since there seems to be no reaction when it is switched and it feels soft. AND I need to switch forums, just realized it is an '86 F250. oops.