The 2001 Lincoln Navigator does
not have a separate on/off switch for the fuel pump. The fuel pump is controlled by the vehicle's computer (PCM - Powertrain Control Module). It activates the pump when the ignition is turned on and the engine needs fuel. It shuts off the pump when the engine is off or under certain conditions (like a crash).
There's no user-accessible switch to manually turn it on and off. If you're having fuel pump issues, it's likely a problem with the pump itself, the fuel pump relay, the PCM, or the wiring. You'll need a mechanic or diagnostic tools to troubleshoot the problem.
