Dual gas tank issue

[Mild Thunder]

Everything has been working fine. Yesterday, i stopped for gas, and filled my driver side tank. I left gas station and flipped switch to driver side, and the engine stumbled for a second, then was fine. Later in the day, i was driving down the road, and engine began coughing, and finally stalled. Pulled over, and couldnt get it running. Switched to passenger tank, started right up. Tried going back to driver side, and stalled again.

So, is this a bad switch? Fuel pump? etc? Truck is a 1989 Dually crew cab with 454 TBI. Everything original. Thanks

[DnStClr]

At this point it is just a guess as to what has failed. You need to do some troubleshooting to narrow down the culprit. To start, do you have an electrical tester-an ohmmeter or 12 volt circuit test light so you can check the dash switch ?
Or-Is it possible the new gas in the drivers side tank is bad?

[beastie_3]

It seems either your in cab switch has gone bad, or it is your selector valve under the truck. Make sure all wires running to each device are in good condition and all grounds are good. If your gas gauge reads properly when you switch over to the bad tank, it might be the selector valve. Even with bad gas, it should still run. Plus you would possibly hear something on the news.

[beastie_3]

A kinked line might be possible too.

[Mild Thunder]

It seems either your in cab switch has gone bad, or it is your selector valve under the truck. Make sure all wires running to each device are in good condition and all grounds are good. If your gas gauge reads properly when you switch over to the bad tank, it might be the selector valve. Even with bad gas, it should still run. Plus you would possibly hear something on the news.

Gas gauge is reading correctly when i switch to the problem tank. So you think it could be the selector valve? Where is that located?

[beastie_3]

Usually along the frame near the tank. Possibly on the passenger side.