[wilkin250r]

Bingo. Hatzie nailed it. With the 3-port valve, the fuel gauge is controlled at the switch in the cab, not at the valve. If you've got a bad valve, the fuel gauge might still work just fine.

Basically, it means that just because the fuel gauge switches, doesn't necessarily mean the valve is also switching. You may very well indeed have a bad valve.

Of course, there is also the distinct possibility you have a good valve but bad wiring, or a bad fuel hose, or a host of other possibilities. But just because your fuel gauge switches doesn't mean the valve is also switching, that logic would only apply to the newer 6-port valves with multiple wires running to them.

So, your next step should be to verify that you are indeed getting power to your valve, and that should be the green wire that attaches to the valve (the ground is made to the frame). It should read zero volts when the passenger side tank is selected, and +12 volts when the driver side tank is selected.

If that test passes (you get the correct readings), it's time to take the valve off and test it on a bench.