If you are an owner of a Mercury Mountaineer and you are experiencing problems with the electrical system, it is likely that a fuse has blown. In this article, we will provide you with a comprehensive Mercury Mountaineer fuse diagram, a detailed explanation of what fuses are and how they work, and a list of frequently asked questions, to help you better understand your vehicle’s electrical system.
What are Fuses?
Fuses are electrical safety devices that protect an electrical circuit from excessive current flow. They are essentially pieces of wire that are designed to melt and break the circuit when too much current passes through them. This prevents damage to the electrical system of your vehicle and its components, such as the battery, alternator or the radio.
Each fuse in your vehicle is rated for a specific amperage or current flow. When a fuse blows, it is usually an indication that there is a problem with the electrical system, which should be diagnosed and repaired before replacing the blown fuse.
Mercury Mountaineer Fuse Diagram
Below is a comprehensive Mercury Mountaineer fuse diagram that shows the location and function of each fuse in the vehicle. The diagram is sorted by location, meaning you can easily find the fuse you are looking for based on where it is located in the car.
| Fuse Location | Fuse Function |
|---|---|
| 1 | Not used |
| 2 | Not used |
| 3 | Not used |
| 4 | Not used |
| 5 | Powertrain Control Module (PCM) Relay |
| 6 | Blower motor relay, Rear blower motor relay, Climate control assembly, Heater control valve |
| 7 | Interior courtesy lamps, Cargo area lamp, Power mirrors, Power antenna, Memory seats and pedals relay |
| 8 | Not used |
| 9 | Powertrain control module, Fuel injectors, Fuel pump relay, Idle air control valve, Mass Airflow sensor |
| 10 | Powertrain Control Module (PCM) Power Relay |
| 11 | Starter relay, Ignition switch |
| 12 | Not used |
| 13 | Power seats, Adjustable pedals |
| 14 | Not used |
| 15 | Horn relay |
| 16 | Instrument cluster, Brake shift interlock solenoid, Speed Control Deactivation Switch |
| 17 | Power windows |
| 18 | 4-Wheel Anti-lock Brake System (ABS) module, Brake fluid level switch |
| 19 | Daytime Running Lamps (DRL) Relay |
| 20 | Fog lamp relay |
| 21 | Trailer tow park lamps relay |
| 22 | Power door locks, Remote entry module |
| 23 | Anti-theft transceiver, Instrument cluster |
| 24 | Not used |
| 25 | Powertrain Control Module (PCM) Keep Alive Memory |
| 26 | Not used |
| 27 | Trailer tow battery charge relay |
| 28 | Trailer tow backup lamps relay |
| 29 | Not used |
| 30 | Trailer tow 7-pin connector relay |
| 31 | Not used |
| 32 | Not used |
| 33 | High-beam headlamps |
| 34 | Low-beam headlamps |
| 35 | Fog lamps, Instrument cluster (battery voltage) |
| 36 | Not used |
| 37 | Trailer tow electric brake controller, Brake pedal position switch |
| 38 | Heated mirrors relay |
| 39 | Trailer tow stop/turn relay |
| 40 | Anti-lock Brake System (ABS) module, Speed control servo, Brake shift interlock solenoid |
Explanation of Fuse Functions
Now let’s take a closer look at the functions of each fuse in the Mercury Mountaineer.
Fuse #5 – Powertrain Control Module (PCM) Relay: This fuse provides power for the Powertrain Control Module (PCM). If this fuse blows, the engine may not start or may stall while driving.
Fuse #6 – Blower Motor Relay, Rear Blower Motor Relay, Climate Control Assembly, Heater Control Valve: This fuse powers the climate control system in the vehicle. If the air conditioning or heating system fails to work, this fuse may have blown.
Fuse #7 – Interior Courtesy Lamps, Cargo Area Lamp, Power Mirrors, Power Antenna, Memory Seats and Pedals Relay: This fuse powers the interior lights in the vehicle, along with the cargo area lamp, power mirrors, power antenna, and memory seats and pedals. If any of these systems fail to work, check this fuse.
Fuse #9 – Powertrain Control Module, Fuel Injectors, Fuel Pump Relay, Idle Air Control Valve, Mass Airflow Sensor: This fuse provides power for the Powertrain Control Module (PCM), fuel injectors, fuel pump relay, idle air control valve, and mass airflow sensor. If the engine misfires, idles roughly, or stalls, this fuse may have blown.
Fuse #10 – Powertrain Control Module (PCM) Power Relay: This fuse provides power for the Powertrain Control Module (PCM) power relay. If this fuse blows, the engine may not start or may stall while driving.
Fuse #11 – Starter Relay, Ignition Switch: This fuse powers the starter relay and ignition switch. If the engine does not crank when the key is turned, check this fuse.
Fuse #13 – Power Seats, Adjustable Pedals: This fuse powers the power seats and adjustable pedals. If either of these systems fail to work, check this fuse.
Fuse #15 – Horn Relay: This fuse powers the horn relay. If the horn does not work, check this fuse.
Fuse #16 – Instrument Cluster, Brake Shift Interlock Solenoid, Speed Control Deactivation Switch: This fuse powers the instrument cluster, brake shift interlock solenoid, and speed control deactivation switch. If any of these systems fail to work, check this fuse.
Fuse #17 – Power Windows: This fuse powers the power windows in the vehicle. If any of the windows fail to work, check this fuse.
Fuse #18 – 4-Wheel Anti-lock Brake System (ABS) Module, Brake Fluid Level Switch: This fuse powers the 4-wheel Anti-lock Brake System (ABS) module and brake fluid level switch. If the ABS warning light comes on, check this fuse.
Fuse #19 – Daytime Running Lamps (DRL) Relay: This fuse powers the daytime running lamps (DRL) relay. If the daytime running lamps fail to work, check this fuse.
Fuse #20 – Fog Lamp Relay: This fuse provides power to the fog lamps. If the fog lamps fail to work, check this fuse.
Fuse #21 – Trailer Tow Park Lamps Relay: This fuse powers the park lamps on a trailer that is being towed. If the trailer park lamps fail to work, check this fuse.
Fuse #22 – Power Door Locks, Remote Entry Module: This fuse provides power to the power door locks and remote entry module. If the power door locks fail to work, check this fuse.
Fuse #23 – Anti-theft Transceiver, Instrument Cluster: This fuse provides power to the anti-theft transceiver and instrument cluster. If the anti-theft system fails to work or if the instrument cluster does not function properly, check this fuse.
Fuse #25 – Powertrain Control Module (PCM) Keep Alive Memory: This fuse provides power to the Powertrain Control Module (PCM) Keep Alive Memory. If this fuse blows, the engine may not start or may stall while driving.
Fuse #27 – Trailer Tow Battery Charge Relay: This fuse provides power to the trailer tow battery charge relay. If the battery on a trailer that is being towed fails to charge, check this fuse.
Fuse #28 – Trailer Tow Backup Lamps Relay: This fuse powers the backup lamps on a trailer that is being towed. If the trailer backup lamps fail to work, check this fuse.
Fuse #30 – Trailer Tow 7-Pin Connector Relay: This fuse powers the 7-pin trailer tow connector. If the connector fails to work, check this fuse.
Fuse #37 – Trailer Tow Electric Brake Controller, Brake Pedal Position Switch: This fuse provides power to the trailer tow electric brake controller and brake pedal position switch. If the trailer brakes fail to work, check this fuse.
Fuse #38 – Heated Mirrors Relay: This fuse provides power to the heated mirrors relay. If the heated mirrors fail to work, check this fuse.
Fuse #39 – Trailer Tow Stop/Turn Relay: This fuse powers the stop and turn signals on a trailer that is being towed. If the trailer stop or turn signals fail to work, check this fuse.
Fuse #40 – Anti-lock Brake System (ABS) Module, Speed Control Servo, Brake Shift Interlock Solenoid: This fuse provides power to the Anti-lock Brake System (ABS) module, speed control servo, and brake shift interlock solenoid. If any of these systems fail to work, check this fuse.
FAQs
1. Why do fuses blow?
Fuses blow when too much current flows through the circuit, usually due to a short circuit or overload in the electrical system. This can be caused by a faulty component or wiring, or by adding too many electrical accessories to the vehicle.
2. How can I tell if a fuse is blown?
To check if a fuse is blown, look for the metal wire inside the fuse. If it is broken or burnt, the fuse has blown and needs to be replaced.
3. How do I replace a blown fuse?
Replacing a blown fuse is relatively simple. Locate the fuse box in your vehicle, which is usually under the dashboard or in the engine compartment. Remove the cover and locate the blown fuse. Using a fuse puller or needle-nose pliers, gently remove the blown fuse and replace it with a new one of the same amperage rating. Replace the cover and test the circuit to ensure it is working properly.
4. Can I use a higher amperage fuse to replace a blown fuse?
No. Using a fuse with a higher amperage rating than what is specified for your vehicle can lead to damage of the electrical system and potentially cause a fire. Always use a fuse with the same amperage rating as the original.
5. How can I prevent fuses from blowing?
To prevent fuses from blowing, avoid overloading the electrical system by not adding too many electrical accessories to your vehicle. Also, make sure all wiring and components are in good condition and replace any that are damaged or worn. Regular maintenance of the electrical system can also help prevent problems from arising.
We hope this article has helped you understand the Mercury Mountaineer fuse diagram and the functions of each fuse in the vehicle. If you are experiencing problems with the electrical system, be sure to check the fuses first.
