starfishkiller

Steve:
Thanks for your reply. I went out and jumpered the front fuel pump, and also jumpered the front fuel sender. As expected the gauge read nearly full for the front tank. I then jumpered the rear fuel pump, and rear fuel sender. The gauge read around quarter tank. These guage readings matched the readings obtained using the switch.

I then drove the truck to a gas station, and pumped $20.00 worth of gas in the rear tank. It took it all and that pushed the gas gauge up to three quarter tank. I tried to put some gas in the front tank, but it wouldn't take it. So, I think the gauge is measuring the amount of fuel in each tank correctly.

I am aware of the fuel tank return line issue with fuel being transferred from one tank to the other. However, this truck has the one way valves for the recall installed.

Is there a way for the running pump to receive fuel from the other tank? I know there are valves and such in the fuel pump/sender modules in each tank. Is there some failure mode that would cause my symptoms?

Thanks
eric