How do you reset the fuel pump or security breaker on a 1999 Lincoln Navigator?

There isn't a reset button or breaker specifically for the fuel pump in the sense of a simple push-button reset like some other car systems. The 1999 Lincoln Navigator's fuel pump system is controlled by the PCM (Powertrain Control Module) and its associated circuits. Issues preventing the fuel pump from running are typically due to:

* Low fuel: Sounds obvious, but make sure you have sufficient fuel in the tank.

* Faulty fuel pump: This is the most common reason. The pump itself might have failed, or there could be a problem with the pump's wiring or relay.

* Faulty fuel pump relay: This small electrical component switches power to the fuel pump.

* Problems in the fuel pump circuit: A blown fuse, damaged wiring, or a problem within the PCM could interrupt power.

* Security system issues (unlikely to directly prevent the pump from running): While the security system can prevent the engine from starting, it generally doesn't directly cut power to the fuel pump unless there's a major fault. If you suspect a security issue, consult a mechanic or dealer.

Troubleshooting Steps:

1. Check the fuel level: Ensure you have enough gas.

2. Check the fuses: Consult your owner's manual to locate the fuel pump fuse (or any fuses related to the fuel system) and check for a blown fuse. Replace if necessary.

3. Check the fuel pump relay: Again, consult the owner's manual to locate and inspect the fuel pump relay. You can sometimes swap it with a similar relay (if you have one) to see if that solves the issue.

4. Listen for the fuel pump: When you turn the ignition key to the "ON" position (not starting the engine), you should hear a brief whirring sound from the fuel pump in the fuel tank. This indicates the pump is receiving power and priming the system. If you don't hear it, there's a problem with power to the pump.

5. Have a professional diagnose the issue: If you've checked the above and are still having problems, take your Navigator to a qualified mechanic or auto electrician. They have the tools and expertise to diagnose the issue, whether it's a bad fuel pump, relay, wiring, or PCM problem.

Important Note: Trying to bypass safety systems or directly manipulate the fuel pump wiring without the proper knowledge can be dangerous and could damage your vehicle's electrical system. It's best to rely on professional diagnosis and repair if you're unsure of what to do.