Maintaining your 2005 Mercury Mountaineer involves understanding its electrical system, and two key components for diagnostics and repair are the OBD2 port and fuse boxes. Whether you’re trying to read diagnostic trouble codes or replace a blown fuse, knowing the location of these elements is crucial. This guide will walk you through finding the OBD2 port and understanding the fuse box locations and layouts for your 2005 Mercury Mountaineer, and also covers models from 2002-2004 as they share similar configurations.
Locating the OBD2 Port on Your 2005 Mercury Mountaineer
The On-Board Diagnostics II (OBD2) port in your 2005 Mercury Mountaineer is your gateway to understanding your vehicle’s health. Mechanics and DIYers use this port to connect scan tools and read diagnostic trouble codes (DTCs), which can pinpoint issues within the engine, transmission, emissions system, and more.
For the 2005 Mercury Mountaineer, the OBD2 port is typically located inside the cabin on the driver’s side. You’ll usually find it beneath the dashboard, in the vicinity of the steering column. It might be directly visible or tucked slightly under the dash, but it’s designed to be easily accessible.
Once you’ve located the OBD2 port, you can plug in a compatible OBD2 scanner. These scanners range from basic code readers to advanced professional tools. Reading the DTCs can give you a starting point for diagnosing a variety of car problems, from a simple sensor malfunction to more complex mechanical issues. While this article focuses on the location of the OBD2 port and fuse boxes, remember that professional diagnosis and repair may be necessary depending on the nature of the problem indicated by the OBD2 codes.
Understanding the Fuse Boxes of Your 2002-2005 Mercury Mountaineer
Your Mercury Mountaineer (2002-2005) utilizes multiple fuse boxes located in different areas of the vehicle. These fuse boxes protect the electrical circuits from overloads. Knowing their locations and layouts is essential for troubleshooting electrical problems like non-functioning lights, accessories, or systems. This guide details the locations and fuse assignments for the passenger compartment fuse box, the engine compartment fuse box, and the rear relay box.
Passenger Compartment Fuse Box
Fuse Box Location
The primary fuse box inside your Mercury Mountaineer is located within the passenger compartment. Specifically, you can find it under the instrument panel on the driver’s side.
Passenger compartment fuse box location in a Mercury Mountaineer (2002-2005), positioned under the dashboard on the driver's side.
Fuse Box Diagram
Below is the diagram for the passenger compartment fuse box, applicable for Mercury Mountaineer models from 2002 to 2005. This diagram illustrates the position of each fuse within the panel.
Diagram of the interior fuse box for Mercury Mountaineer (2002, 2003, 2004, 2005), showing fuse positions and numbers.
Passenger Compartment Fuse Assignment Table
The following table details the function, amperage, and position of each fuse within the passenger compartment fuse box. Note that some fuse assignments may vary slightly between model years (2002 and 2003-2005), so pay close attention to the year-specific details.
№ | 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 |
Notably, fuse #24 (15A) in the passenger compartment fuse box is designated for both the cigar lighter and the OBD II port. If you are experiencing issues with your OBD2 port, checking this fuse is a good first step.
Top Side Relays (Passenger Compartment Fuse Box)
On the reverse side of the passenger compartment fuse panel, you’ll find several relays. Accessing these relays requires removing the fuse panel itself.
Top view of the passenger compartment fuse panel in a Mercury Mountaineer (2002, 2003, 2004, 2005), showing relay locations.
№ | 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) |
Engine Compartment Fuse Box
Fuse Box Location
The power distribution box, another name for the engine compartment fuse box, is located in the engine compartment. You’ll find it on the driver’s side, under a protective cover.
Fuse Box Diagram (2002)
For 2002 Mercury Mountaineer models, the engine compartment fuse box layout is as depicted below:
Fuse box diagram for the engine compartment of a 2002 Mercury Mountaineer, detailing fuse and relay positions.
Engine Compartment Fuse and Relay Assignment (2002)
The following table outlines the fuses and relays within the engine compartment fuse box for 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 |
* Mini Fuses ** Maxi Cartridge Fuses |
Fuse Box Diagram (2003-2005)
For Mercury Mountaineer models from 2003 to 2005, the engine compartment fuse box layout is slightly different, as shown in the diagram below:
Engine Compartment Fuse and Relay Assignment (2003-2005)
The table below details the fuse and relay assignments for the engine compartment fuse box in 2003-2005 Mercury Mountaineer models. Again, note minor year-to-year variations.
№ | 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 |
* Mini Fuses ** Cartridge Fuses |
Rear Relay Box
Relay Box Location
The rear relay box in the Mercury Mountaineer (2002-2005) is located in the rear of the vehicle. Specifically, it’s positioned on the rear passenger side quarter trim panel.
Rear relay box location in a Mercury Mountaineer (2002, 2003, 2004, 2005), found on the rear passenger side quarter trim panel.
Rear Relay Box Assignment
Here’s a table detailing the relay assignments for the rear relay box. Note the variations between the 2002-2003 models and the 2004-2005 models.
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 |
Conclusion
Understanding the locations and functions of the OBD2 port and fuse boxes in your 2005 Mercury Mountaineer is a vital part of vehicle maintenance and troubleshooting. This guide provides you with the necessary information to locate these components and interpret their layouts. Remember to always consult your vehicle’s owner’s manual for the most accurate and up-to-date information, and when in doubt, seek professional automotive repair assistance. Regularly checking your fuses and utilizing the OBD2 port for diagnostics can help you keep your Mercury Mountaineer running smoothly for years to come.