Hello, I have been having trouble with the fuel tank distribution system on my '88 F-250. Lately it quit drawing from the rear tank. I have been running it on the front tank , but had the idea to try to run off the rear tank as it is full. For a couple of weeks I had the dash switch turned to the rear tank and it seemed to be running ok, though the guage never moved. Finally it ran out of fuel, while still showing a full tank. Here it was running on the front tank while the dash switch was set to the rear tank. Even the guage showed the rear tank level, which never moved as the truck ws running off the front tank. I was wondering how this could be. Is there a valve that is switched by the dash switch? One that might not be switching all the way? I always thought that the dash switch only changed the fuel guage and the power to the tank fuel pump? Does it also operate an electric fuel valve?
I know this is all confusing. Thanks for any help you all can give. YC

 

Your rear pump went out back then....then,when you switched to front tank...the front pump moved the dual selector vavle to the front tank mode......only until you get the rear pump to move the selector valve to the rear tank mode will it work right...either a bad rear pump or no juice/ground to the pump or stuck in front mode dual selector valve.