Mercury Mountaineer 2003 Fuse Box Info
Passenger compartment fuse box location:
The fuse box is located below the instrument panel on the driver’s side.
Engine compartment fuse box location:
Fuse Box Diagram | Layout
Passenger compartment fuse box:
| Fuse/Relay N° | Rating | Functions |
| 1 | 30A | Memory seat module, Driver power seat |
| 2 | 20A | Heated seats, Moonroof |
| 3 | 20A | Radio, Amplifier, DVD |
| 4 | 5A | Front wiper module |
| 5 | 15A | Flasher Relay (Turn, Hazards) |
| 6 | 10A | Right Horn |
| 7 | 15A | Heated Mirrors |
| 8 | - | Not used (spare) |
| 9 | - | Not used (spare) |
| 10 | 10A | Heated backlight relay coil, Heated seat module, A/C clutch contact |
| 11 | - | Not used (spare) |
| 12 | 5A | 4x4 module |
| 13 | 5A | Overdrive cancel switch, Flex fuel sender |
| 14 | 5A | PATS Module |
| 15 | 5A | Rear wiper module, Cluster, TPMS |
| 16 | 5A | Power mirror, Manual climate control, TPMS |
| 17 | 15A | Delayed acc. coil, Battery saver, Glove compartment lamp, 2nd row courtesy lamps |
| 18 | 10A | Left Horn |
| 19 | 10A | RCM |
| 20 | 5A | Driver seat switch, Memory switch, Driver seat module, BSM, Sunload sensor |
| 21 | 5A | Instrument cluster, Compass, Flasher coil |
| 22 | 10A | ABS, IVD Controller |
| 23 | 15A | Brake pedal position switch, Driver brake applied relay, Redundant cruise deactivate switch |
| 24 | 15A | Cigar lighter, OBD II |
| 25 | 5A | Mode-Temperature actuator for auxiliary climate control, Trailer tow battery charge coil |
| 26 | 7.5A | Park aid, Brake shift interlock, Approach lamp relay coil, IVD switch |
| 27 | 7.5A | Electrochromatic mirror, Digital transmission range sensor - backup lamps |
| 28 | 5A | Radio (Start)/DVD (Start) |
| 29 | 10A | Digital transmission range sensor, PWR feed to fuse #28 (Start feed) |
| 30 | 5A | Daytime Running Lamps (DRL), Remote solenoid, DEATC climate controller, Manual climate control, Manual climate control temp blend actuator |
Passenger compartment fuse box - top side (These relays are located on the reverse side of the passenger compartment fuse panel):
| Fuse/Relay N° | Rating | Functions |
| Relay 1 | - | Flasher Relay |
| Relay 2 | - | Rear Defrost |
| Relay 3 | - | Delayed Accessory Relay |
| Relay 4 | - | Open |
| Relay 5 | - | Battery Saver |
| Relay 6 | - | Open |
| Relay 7 | - | Open |
Engine compartment fuse box:
| Fuse/Relay N° | Rating | Functions |
| 1 | 60A | PJB |
| 2 | 30A | BSM |
| 3 | - | Not Used |
| 4 | 30A | Rear defrost |
| 5 | 40A | Anti-lock Brake System (ABS) pump |
| 6 | 60A | Delayed accessory |
| 7 | 20A | Power Point #2 |
| 8 | - | Not Used |
| 9 | 20A | Power Point #1 |
| 10 | 30A | ABS module (valves) |
| 11 | 40A | PTEC |
| 12 | 50A | Ignition relay, Starter relay |
| 13 | 40A | Trailer tow battery, Trailer tow turn signals |
| 14 | 10A | Daytime Running Lamps (DRL) (Canada) |
| 15 | 15A | Memory (PCM/DEATC/Cluster) |
| 16 | 15A | Headlamp switch, Foglamp switch |
| 17 | 20A | 4 x 4 (v-batt 2) |
| 18 | 20A | 4 x 4 (v-batt 1) |
| 19 | 20A | High Beam Relay |
| 20 | 30A | Electric Brake |
| 21 | 30A | Front wiper motor |
| 22 | 20A | Low beam |
| 23 | 30A | Ignition Switch |
| 24 | - | Not used |
| 25 | - | Not used |
| 26 | 15A | Fuel Pump |
| 27 | 20A | Trailer Tow Lamps |
| 28 | 20A | Horn relay |
| 29 | 60A | PJB |
| 30 | 20A | Rear wiper motor |
| 31 | - | Not Used |
| 32 | - | Not Used |
| 33 | 30A | Auxiliary Blower Motor |
| 34 | 30A | Passenger power seat, Adjustable pedals |
| 35 | - | Not Used |
| 36 | 40A | Blower Motor |
| 37 | 15A | A/C clutch relay, Transmission |
| 38 | 15A | Coil On Plug |
| 39 | 15A | Injectors, Fuel pump relay |
| 40 | 15A | PTEC Power |
| 41 | 15A | HEGO, UMV, CMS, PTEC |
| 42 | 10A | Right Low Beam |
| 43 | 10A | Left Low Beam |
| 44 | 15A | Front foglamps |
| 45 | 2A | Brake pressure switch (ABS) |
| 46 | 20A | High beams |
| 47 | - | Horn relay |
| 48 | - | Fuel Pump Relay |
| 49 | - | High Beam Relay |
| 50 | - | Fog Lamp Relay |
| 51 | - | DRL relay (Canada)/AdvanceTrac relay (U.S.) |
| 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 | - | PTEC Relay |
| 58 | - | Ignition Relay |
| 59 | - | Driver brake applied relay (vehicles equipped with AdvanceTrac only) |
| 60 | - | PCM Diode |
| 61 | - | A/C Clutch Diode |
| 62 | 30A | Power windows circuit breaker |
Rear Relay Box (The relay box is located on the rear passenger side quarter trim panel):
| Fuse/Relay N° | Rating | Functions |
| Relay 14 | - | Not used |
| Relay 15 | - | Trailer Tow back up lamps |
| Relay 16 | - | Not Used |
| Relay 17 | - | Not used |
| Relay 18 | - | Not used |
| Relay 19 | - | Trailer Tow Park Lamps |
| Relay 20 | - | Trailer Tow Battery Charge |
| Relay 21 | - | Not Used |
| Relay 22 | - | Approach Lamps |
| Relay 23 | - | Not Used |
| Diode 3 | - | Not Used |
| Diode 4 | - | Not Used |
Auxiliary relay box - Canadian vehicles equipped with AdvanceTrac (The relay box is located on the front right fender well underneath the speed control module):
| Fuse/Relay N° | Rating | Functions |
| Relay 64 | - | AdvanceTrac relay |
| Relay 65 | - | Open |
| Relay 66 | - | Open |
