Hi and thanks for the site. I'm a rookie and this is my first post. She is an 86 f250 7.5 two wheel drive. Just bought it and everything worked but the rear tank. Figured it was the selector switch. Took the dash apart and tried switching. Truck ran for a few and then died. Went back to the front tank. Now front tank not working, no gas guage in either direction too! I knew I should have left it alone.... Pulled switch out and got to 6 plug connector. Burned ground wire (black) and lots of bad wiring behind the switch. Cleaned up wiring and checked switch, no start, no gas guage. Checked fuses at block, none blown. Checked fuseable links at solenoid, all are good. Got proper wiring diagram, made sure all wires were in the correct plug position in switch. Checked for power to switch. Only get power to switch when starter is cranking and then shortly after I stop cranking . Otherwise there is no full time power to this switch. It looks like there should be power to this switch as soon as the key is on but my fuse block doesn't seem to have a #15 10 amp socket. I am baffled how the gas guage gets power from the switch. Is it through the tank selector valve switch? Can anyone give me an idea what to do next here. Its a really pretty truck with no rust. Any ideas guys?? Remember, its a 460, not fuel injected with a electrical tank selector valve.
The power goes directly to the relay when Cranking.
When in Run the power travels through the inertia (safety) switch and the oil pressure cut out controls the relay.
If you have no oil pressure, or that wiring is damaged the truck will not continue to run.
BTW, this post should be in the 80-86 forum, not the 87-96.
Perhaps a moderator will move it.
You may get better answers there.
My selector switch has 6 wires, two R, one R&B two B&W and one Black. However your diagram looks like it has only three? Other than that it looks more correct than the one that I have that shows 6 wires going to the selector switch. I think I will follow yours, it has no fuses at the fuse box and that had me baffled as all my fuses tested good. I am leaning towards the selector valve or the yellow fuse link as I tested the blue one . I need to get some time to pull it into my warm garage, but like most 460's these days, its not my daily driver. Thanks for the reply and also for pointing out the wrong year forum for me. Maybe a moderator will take pitty on a first timer and move me to the correct decade. I may not need it now though thanks to you getting me this diagram. I will let you know if I get it running. Thanks Jim!