I had a 1980 ford F-150 truck given to me and it has been abused. This sounds like a dumb question, but where is the switch, that changes from one tank to the other, located? Can you bypass the selector valve? I did try bypassing the valve and it appears that the fuel is draining back into the tank, after the engine is switched off.

 

The switch is under the dash.... Right about even with your knees if my memory serves. You should be able to reach down from the driver's seat.

If you've got a bad valve, any auto parts store should have them. They're not expensive and a common failure item.

-Joe

 

Joe, is this a toggle switch? Is it obvious what it is?

 

should be a toggle. labelled with an F and R

 

Well, it appears that the switch and the wiring have been removed. I knew that I wasn't that stupid.