When I switch from my front fuel tank to my rear tank gas stops

The seal in the selector valve is bad on the front side.
Replace the valve or rebuild it.
Disconnect the battery ground cable before doing any work around gasoline.

Sounds like the selonoid at the switching valve is not working.

I am guessing that your truck is a Diesel. There is no electric fuel pump on the diesel models. The fuel filter light comes on when there is not enough fuel pressure. Possible problems include the selector vavle not fully switching, and/or an obstruction in the pick up in the front tank.

the selector valve is located underneath the truck on the inside of the frame rail on the drivers side If I remember right. Try swtiching to the front tank and tapping the selector valve assembly. If that clears up the light then the selector valve is sticking and needs to be repaired or replaced.

the selector is located between the two tanks and has 3 or 4 fuel lines connected to it as well as wires if its an electrical switch.some had a manual switch which is usually behind the front seat on the floor that switches the tanks from one to the other when turned.

If fuel injected. the tank selector valve switches both the suction line from the tank and the return line back to the tank. It sounds like you have a stuck or bad tank selector valve if the return is not being ported back to the rear tank.

fuel tank selector switch

the tank selector valve is stuck or not switching when u switched ur tanks

the fuel tank switch valve is bad. It is pumping fuel to the other tank instead of the engine. There was a recall for some models in 1989-91. I think you need a selector valve, just my guess.

here is some of what it says:

Your truck is equipped with a dual fuel tank selector valve which is designed to direct fuel to the engine from one fuel tank and returns unused fuel to the same tank. It is possible that the dual fuel tank selector valve on your truck could leak internally and as a result return a portion of the unused fuel to the tank other than from which it was drawn. Should this occur when the other tank is at full capacity, fuel could flow out the filler pipe of the tank past the cap. Fuel spillage in the presence of an ignition source, presents the potential for a vehicle fire.

Just in front of the side tank is the selector.Very common problem.The rear fuel tanks pump quits.

I’m happy to assist further over the phone at https://www.6ya.com/expert/joe_a3369546f8067589

I had the same problem with my 89 f-150 and the solution was replacing the six port selector valve located under the driverside on the frame rail. Just about right under the driver seat.