dual tanks bad pump.

[pieceofchevy]

i am working on a 1988 GMC with dual tanks and a dump flatbed that was added later. one on the drivers' side works but the one on the passenger side doesn't. got the old pump out but haven't been able to drop the tank and there is no power to the connector. the wiring is all jacked up. i flipped the switch and still no power. i can hear the valve click but not sure of the wiring to the fuel valve. does anyone have a wiring diagram for the fuel system? the bad tank has 10 yr old gas and it is up to 1/3 of nasty gas. worse than taco bell tuesday.

 

[Nad_Yvalhosert]

Driver and passenger fuel tanks? Gotta be a squarebody, huh? 400's dont have a switch. The front level sensor activates the rear tanks pump, which fills the front tank while you're driving. But they're only on the Chassis Cab 3500's.

Chilton's or Haynes has schematics printed in their manuals. Available at most autoparts stores or ebay...