1996 F150 4.9 5 SPEED FUEL PUMP RELAY CLICKS WHEN I TURN KEY TO PRIME. FRONT PUMP. RUNS FOR 3 SECONDS AND DIES. SWITCH TO THE REAR TANK TURN KEY F/P. PRIMES AND TRUCK RUNS ALL DAY UNTIL THE FUEL IN THE REAR TANK IS SUCKED TO THE FRONT TANK NOW I HAVE FULL FRT TANK AND SHOULD I PUT MORE IN THE REAR TANK. WILL FUEL STAY IN TANK OR TRY TO SUCK TO THE FRONT TANK. ALSO CHECK ENGINE LIGHT STAYS ON ALL THE TIME GOT CODES PO232 F/P SECONADARY CIR. HIGH AND PO704 CLUTCH SWITCH. INPUT CIR.
The two tanks are designed to work together and so BOTH pumps must be functioning and, as well, the related fuel system supply code, the Code P0232 that has set has to be resolved. P0232 means that the fuel pump relay is stuck on, keeping power supplied to the fuel pump even after the ignition has been turned off although another possibility is the fuel pump secondary power circuit has a short to battery voltage. The factory service manual (FSM) specifies a very lengthy diagnostic (because you have separate tanks). If you do not have the FSM, your best bet is to request a fuel pump diagnostic - dual tanks and let a certified mechanic get to the bottom of this. With regard to the other code, P0704, that code will set if the clutch switch is defective, there is worn clutch pedal lever or clutch lever bushing, shorted or open wiring and/or connectors in the clutch switch circuit, a blown fuse or burnt fusible link and/or, rarely, a faulty PCM or programming error. If you request the pump diagnostic the responding certified mechanic will get this taken care of for you. If you have further questions or concerns, do not hesitate to re-contact YourMechanic as we are always here to help you.
Our certified mechanics come to you ・Backed by 12-month, 12,000-mile guarantee・Fair and transparent pricing