Understanding your 2005 Mercury Mountaineer’s onboard diagnostics (OBD2) port and fuse boxes is crucial for both routine maintenance and troubleshooting potential electrical issues. As a seasoned auto repair expert at techcarusa.com, I’ll guide you through locating these essential components, ensuring you’re well-equipped to keep your Mountaineer running smoothly. While many articles cover fuse box diagrams, this guide goes a step further by pinpointing the OBD2 location and providing comprehensive fuse box information, making it a superior resource for English-speaking car owners.
Decoding Your 2005 Mercury Mountaineer: OBD2 Port and Fuse Boxes
The 2005 Mercury Mountaineer, part of the second generation (2002-2005), is equipped with an OBD2 port, a standardized interface used for accessing the vehicle’s diagnostic information. This port is invaluable when diagnosing issues like a check engine light or for routine emissions testing. Alongside the OBD2 port, understanding your vehicle’s fuse boxes is equally important. Fuses protect your car’s electrical circuits from overloads, and knowing their locations and functions can save you time and money on repairs.
Finding the OBD2 Port in Your 2005 Mercury Mountaineer
The OBD2 port location in a 2005 Mercury Mountaineer is typically under the dashboard on the driver’s side. You’ll usually find it near the steering column, often just below the dash or within the knee bolster area. It’s a 16-pin connector, trapezoidal in shape, and is relatively easy to access without tools.
Once located, you can connect an OBD2 scanner to read diagnostic trouble codes (DTCs), monitor real-time data, and perform other diagnostic functions. This can be incredibly helpful in pinpointing problems, from minor sensor malfunctions to more significant engine or transmission issues.
Mercury Mountaineer (2002-2005) Fuse Box Locations and Diagrams
The 2005 Mercury Mountaineer, like its counterparts in the 2002-2005 range, has multiple fuse boxes located in different areas of the vehicle:
- Passenger Compartment Fuse Box: Located inside the vehicle, under the instrument panel on the driver’s side.
- Engine Compartment Fuse Box: Situated in the engine bay, typically on the driver’s side, near the battery.
- Rear Relay Box: Found in the rear passenger side quarter trim panel.
Let’s delve into each location with diagrams and fuse assignments.
1. Passenger Compartment Fuse Box
Location
As mentioned, the passenger compartment fuse box is positioned beneath the instrument panel on the driver’s side. You may need to crouch down and look under the dash to locate it. It’s usually covered by a plastic panel that can be easily removed by hand.
Diagram and Fuse Assignment
The diagram above illustrates the layout of the fuses within the passenger compartment fuse box. Below is a table detailing the fuse assignments:
| № | Amp | Description |
|---|---|---|
| 1 | 30A | 2002: Radio Sense, 4×4, ABS Control Module / 2003-2005: Memory seat module, Driver power seat, Driver power lumbar |
| 2 | 20A | 2002: Folding Mirror, Moon Roof, Heated Seats, Moon roof / 2003-2005: Heated seats (2003), Moonroof |
| 3 | 20A | Radio, Amplifier, DVT, Power Antenna (2002) |
| 4 | 5A | 2002: Digital Transmission Range Sensor / 2003-2005: Front wiper module |
| 5 | 15A | Flasher relay (Turn, hazards) |
| 6 | 10A | 2002-2003: Right horn / 2004-2005: Key-in-chime |
| 7 | 15A | Heated mirrors |
| 8 | 5A | 2002: Washer Pump Relays (Front and Rear), Front Wiper Control / 2003-2005: Heated PCV (4.0L engine only) |
| 9 | 15A | 2002: Rear Wiper Coil and Contact / 2003-2005: Not used |
| 10 | 10A | 2002-2003: Heated backlight relay coil, Heated seat module, A/C clutch contact, Temp Blend Actuator (2002) / 2004-2005: Heated backlight relay coil, A/C clutch contact |
| 11 | 20A | 2002-2003: Not used (spare) / 2004-2005: Heated seats |
| 12 | 5A | 2002: Foglamp Switch,4×4 module / 2003: 4×4 module / 2004-2005: Not used |
| 13 | 5A | 2002: Over Drive Cancel Switch, GEM Start, Flex Fuel Sender / 2003-2005: Overdrive cancel switch |
| 14 | 5A | PATS |
| 15 | 5A | 2002: 4 x 4, Memory Seat Disable / 2003-2005: Rear wiper module, Cluster, TPMS (2003) |
| 16 | 5A | 2002: Power Mirror, Security Module (turn), Manual Climate Control / 2003-2005: Power mirror, Manual climate control, TPMS |
| 17 | 15A | Delayed accessory relay coil/Battery saver coil and contact/Reading and glove box lamps |
| 18 | 10A | 2002-2003: Left horn / 2004-2005: Flexible fuel pump |
| 19 | 10A | 2002: Not Used / 2003-2005: Restraint Control Module (RCM) |
| 20 | 5A | 2002: Memory Module, GEM Module / 2003: Driver seat switch, Memory switch, Driver seat module, BSM, Sunload sensor / 2004-2005: Memory driver seat switch, Driver seat module, Body Security Module (BSM), PATS LED |
| 21 | 5A | Instrument cluster, Compass, Flasher coil |
| 22 | 10A | 2002: Not Used / 2003-2005: ABS, IVD Controller |
| 23 | 15A | 2002: Brake Pedal Position Switch / 2003: Brake pedal position switch, Driver brake applied relay, Redundant cruise deactivate switch / 2004-2005: Not used |
| 24 | 15A | Cigar lighter, OBD II |
| 25 | 5A | Mode-Temperature actuator for auxiliary climate control, Trailer tow battery charge relay coil, TPMS (2004-2005) |
| 26 | 7.5A | Reverse park aid, Brake shift interlock, Approach lamp relay coil (2003) IVD switch |
| 27 | 7.5A | 2002: Electronic Compass Mirror, Security Module, Digital Transmission Range Sensor – Backup Lamps / 2003-2005: Automatic dimming mirror, Digital transmission range sensor, Backup lamps |
| 28 | 5A | 2002: Air Bag Diagnostics / 2003-2005: Radio (Start)/DVD (Start) |
| 29 | 5A/10A | 2002: 4 x 4, GEM Module signal, ABS Control Module, Moon Roof / 2003-2005: Digital transmission range sensor, PWR feed to fuse #28 (Start feed) |
| 30 | 5A | Daytime Running Lamps (DRL), DEATC climate controller, Manual climate control, Manual climate control temp blend actuator |
Note: Fuse #24 (15A) in the passenger compartment fuse box is responsible for both the cigar lighter and the OBD II port. If you’re experiencing issues with your OBD2 scanner not powering up, checking this fuse is a good first step.
Relays (Top Side)
The passenger compartment fuse panel also houses relays on its reverse side. Accessing these relays requires removing the fuse panel.
| № | Relays |
|---|---|
| 1 | Flasher |
| 2 | Rear defrost |
| 3 | Delayed accessory |
| 4 | Front Washer Pump (2002) |
| 5 | Battery saver |
| 6 | Rear Washer Pump (2002) |
| 7 | Interior Lamps (2002) |
2. Engine Compartment Fuse Box
Location
The engine compartment fuse box, also known as the power distribution box, is located in the engine bay on the driver’s side. It’s usually a black box with a removable cover, often situated near the battery or firewall.
Diagram and Fuse Assignment (2002)
The following table outlines the fuse and relay assignments for the engine compartment fuse box in the 2002 Mercury Mountaineer:
| № | Amp Rating | Description |
|---|---|---|
| 1 | 60A** | PJB |
| 2 | 20A** | Door Locks |
| 3 | 20A** | GCC Pusher Fan (export only) |
| 4 | 30A** | Heated Backlight |
| 5 | 40A** | ABS |
| 6 | 60A** | Circuit Breaker |
| 7 | 20A** | Power Point #2 |
| 8 | — | Not Used |
| 9 | 20A** | Power Point #1 |
| 10 | 20A** | ABS Module |
| 11 | 40A** | PTEC |
| 12 | 50A** | Ignition Relay |
| 13 | 30A** | Trailer Tow Battery |
| 14 | 10 A* | Fog Lamps |
| 15 | 5A* | Memory |
| 16 | 15 A* | Headlamp Switch |
| 17 | 20A* | 4×4 (v-batt 2) |
| 18 | 20A* | 4×4 (v-batt 1) |
| 19 | 20A** | High Beam Relay |
| 20 | 30A** | Electric Brake |
| 21 | Not Used | |
| 22 | 20A** | Autolmap; Low Beam |
| 23 | 30A** | Ignition Switch |
| 24 | 10 A* | Rear Fog Lamps |
| 25 | 20A* | Security Module (horns) |
| 26 | 15A* | Fuel Pump |
| 27 | 20A* | Trailer Tow Lamps |
| 28 | 10 A* | Daytime Running Lamps (DRL) |
| 29 | 60A** | PJB |
| 30 | — | Not Used |
| 31 | Not Used | |
| 32 | Not Used | |
| 33 | 30A** | Auxiliary Blow er Motor |
| 34 | 30A** | Power Seats |
| 35 | — | Not Used |
| 36 | 40A** | Blower Motor |
| 37 | 15A* | A/C Clutch |
| 38 | 15 A* | Coil On Plug |
| 39 | 15 A* | High Beam |
| 40 | 15 A* | PTEC Power |
| 41 | 15 A* | HEGO, UMV, CMS, PTEC |
| 42 | 10 A* | Right Low Beam |
| 43 | 10 A* | Left Low Beam |
| 44 | 10 A* | High Beam Relay |
| 45 | 7.5A* | Right High Beam (export only) |
| 46 | 15 A* | Injectors |
| 47 | — | Daytime Running Lamps Relay, GCC Pusher Fan (export) |
| 48 | — | Fuel Pump Relay |
| 49 | — | High Beam Relay |
| 50 | — | Fog Lamp Relay |
| 51 | — | Autolamp Relay |
| 52 | — | A/C Clutch Relay |
| 53 | — | Park Lamp Relay (export) |
| 54 | — | Wiper Rim / Park Relay |
| 55 | — | Blower Motor Relay |
| 56 | — | Starter Relay |
| 57 | — | PTEC Relay |
| 58 | — | Ignition Relay |
| 59 | — | Wiper High/Low Relay |
| 60 | — | PCM Diode |
| 61 | — | A/C Clutch Diode |
| 67 | 30A CB | Delayed accessory |
Diagram and Fuse Assignment (2003-2005)
For 2003, 2004, and 2005 Mercury Mountaineer models, the engine compartment fuse box layout is slightly different:
| № | Amp | Description |
|---|---|---|
| 1 | 60A** | PJB #1 |
| 2 | 30A** | BSM |
| 3 | — | Not used |
| 4 | 30A** | Rear defrost |
| 5 | 40A** | Anti-lock Brake System (ABS) pump |
| 6 | 60A** | Delayed accessory, Power windows, Audio |
| 7 | 20A** | Power point #2 |
| 8 | — | Not used |
| 9 | 20A** | Power point #1 |
| 10 | 30A** | ABS module (valves) |
| 11 | 40A** | Powertrain Control Module (PCM) |
| 12 | 50 A** | Ignition relay, Starter relay |
| 13 | 40A** | Trailer tow battery charge, Trailer tow turn signals |
| 14 | 10A* | 2003-2004: Daytime Running Lamps (DRL) (Canada) / 2005: Not used |
| 15 | 15A* | Memory (PCM/DEATC/Cluster), Courtesy lamps |
| 16 | 15A* | Park lamps, Autolamp parklamps, Front foglamps relay coil |
| 17 | 20 | 2003: 4×4 (v-batt 2) / 2004-2005: Not used |
| 18 | 20A* | 2004: 4×4 (v-batt 1) / 2004-2005: PCM with two-speed 4×4 clutch |
| 19 | 20A** | High beam relay |
| 20 | 30A** | Trailer electric brake module |
| 21 | 30A** | Front wiper motor |
| 22 | 20A** | Low beam, Autolamp |
| 23 | 30A** | Ignition switch, PCM diode |
| 24 | — | Not used |
| 25 | 15A* | 2003: Not Used / 2004-2005: Brake on-off |
| 26 | 20A* | Fuel pump |
| 27 | 20A* | Trailer tow- park lamps, Trailer tow- back-up |
| 28 | 20A* | Horn relay |
| 29 | 60A** | PJB #2 |
| 30 | 20A** | Rear wiper motor |
| 31 | — | Not used |
| 32 | — | Not used |
| 33 | 30A** | Auxiliary blower motor |
| 34 | 30A** | Passenger power seat, Adjustable pedals (non-memory) |
| 35 | — | Not used |
| 36 | 40A** | Blower motor |
| 37 | 15A* | A/C clutch relay, Transmission |
| 38 | 15A* | 2003: Coil on plug / 2004-2005: HEGO, VMV, CMS, ESM, CVS |
| 39 | 15A* | Injectors, Fuel pump relay coil |
| 40 | 15A* | 2003: PTEC power / 2004-2005: PCM power |
| 41 | 15A* | 2003-2004: HEGO, VMV, CMS, PCM diode, ESM, CVS / 2005: Coil on plug (4.6L engine only), Ignition coil (4.0L engine only) |
| 42 | 10 A* | Right low beam |
| 43 | 10 A* | Left low- beam |
| 44 | 15A* | Front foglamps |
| 45 | 2A* | 2003: Brake pressure switch (ABS) / 2004-2005: Brake pressure switch (non-AdvanceTrac vehicles) |
| 46 | 20A* | High beams |
| 47 | — | Horn relay |
| 48 | — | Fuel pump relay |
| 49 | — | High beam relay |
| 50 | — | Front fog lamps relay |
| 51 | — | 2003: DRL relay (Canada)/AdvanceTrac relay (U.S.) / 2004-2005: DRL relay (Canada) |
| 52 | — | A/C clutch relay |
| 53 | — | Trailer tow right turn relay |
| 54 | — | Trailer tow left turn relay |
| 55 | — | Blower motor relay |
| 56 | — | Starter relay |
| 57 | — | 2003: PTEC relay / 2004-2005: PCM relay |
| 58 | — | Ignition relay |
| 59 | — | 2003: Driver brake applied relay (vehicles equipped with AdvanceTrac only) / 2004-2005: Not used |
| 60 | — | PCM diode |
| 61 | — | A/C clutch diode |
| 62 | 30A CB | Power windows circuit breaker |
3. Rear Relay Box
Location
The rear relay box is located on the rear passenger side quarter trim panel. You may need to access it from the cargo area, behind a trim panel.
| Relay Location | Description |
|---|---|
| 14 | 2002: Rear fog lamps (export) / 2003-2005: Not used |
| 15 | Trailer Tow back up lamps |
| 16 | Not Used |
| 17 | 2002-2003: Rear Wipers / 2004-2005: Not Used |
| 18 | 2002: Trailer Tow Stop EAO / 2003-2005: Not Used |
| 19 | Trailer Tow Park Lamps |
| 20 | Trailer Tow Battery Charge |
| 21 | Not Used |
| 22 | 2002-2003: Approach Lamps / 2004-2005: Not Used |
| 23 | Not Used |
| Diode 3 | Not Used |
| Diode 4 | Not Used |
Maintaining Your 2005 Mercury Mountaineer’s Electrical System
Understanding the 2005 Mercury Mountaineer OBD2 location and fuse box layouts is more than just information; it’s empowerment. Whether you’re diagnosing a check engine light using your OBD2 scanner or replacing a blown fuse to restore power to a circuit, this knowledge helps you maintain your vehicle effectively.
Remember to always consult your owner’s manual for the most accurate and vehicle-specific information. Regularly checking your fuses and being familiar with the OBD2 port are simple steps that can save you from more significant problems down the road.
For further reading on automotive fuses and diagnostics, explore these helpful resources:
- How to check the fuses?
- How to replace a blown fuse?
- Why do car fuses blow?
- Types of automotive fuses
