E46 Rear Fog Light installation

*This information is provided for entertainment and reference purposes only.  Read and understand everything first before even ordering the parts. The procedures described have actually been done but the author makes no guarantees of any kind.  If you are unfamiliar with automotive electronics and vehicle interiors, do not attempt.  Damage caused by unsuccessful execution of of this project may cause damage to the vehicle that may not be covered by the manufacturer's warranty.

Models applicable: All bodystyles including M; pre-facelift taillights only (99-01 sedan, 00-03 coupe/convertible, all touring) front foglights required

OE integration: Excellent

Difficulty: moderate

Cost: $50-$250

Special tools required: none

Scope: This project will add 1 or 2 rear foglights per European models to US spec cars without rear foglights. European regulations only require a single light on the left side in LHD nations and right side in RHD ones.  This installation will support either, or both.

Parts required:
Bushing Contact for LCM 61 13 0 008 998 qty.1
Bushing Contact for lights 61 13 0 006 626 or 61 13 0 007 257 qty.1 per side
Bulb Holder 63 21 8 374 807 Left; 63 21 8 374 808 Right (opt) Bulbs included
Light Switch Unit 61 31 8 378 574: Xenon, no auto lights
61 31 6 911 646: Xenon, auto lights
61 31 8 378 572: Halogen, no auto lights
61 31 6 911 645: Halogen, auto lights
(note, you must get what matches your car; no xenon or auto lights retrofit possible with this project)
Small gauge (18-22AWG) butt connectors
25ft PVC insulated stranded copper wire (20AWG OK for 1 light; 18AWG recommended for 2)

Because BMW provides their contacts with several inches of wire pre-attached, you'll need to crimp/solder/insulate (use your favorite method) the contact assemblies to other wiring.

Rear bulb holder replacement:

• Remove trunklid/hatch carpet.  On all but Touring, remove toolkit by removing 2 screws under the hinge and the strap. Remove the 8 upholstry clips then the carpet.  For touring, unclip the carpeted panel, remove 2 plastic rivets by the latch, remove all screws, and rear wiper motor trim to access 2 more screws.  There are also 2 doorpanel-type clips to pop to remove the large hatch trim.  You will also need to remove the right outside plastic trim (to the right and under the hatch glass) to pass the wiring to the boot at the top of the hatch.
  
• Unplug and unclip original bulb holder(s) and replace with new ones.
• Depending on what you find easier, you can crimp the contacts onto the 25ft wire now, then pass the other end through the trunklid, or pass the wire through the trunklid first, then crimp to the contacts.  Make sure to insulate.
  
• Insert the contact into the empty space in the original wiring plug. Note orientation of contact.
• Use electrical tape, friction tape or zip ties to tie the wiring to existing harnesses. You can try passing the wires through the existing harnesses if you want to try.
• Carefully follow the existing harness path to pass the wire through the wiring boot and into the trunk to the right and above the right rear speaker.

You may want to test your work now by touching the bare end of the long wire to a voltage source (the battery is convenient).  The light(s) under the reverse lens should turn on brightly.

Use whatever path you find convenient to get the wire to the driver's side footwell near the hood release.  You can continue down the right side to the glovebox, then across the dash, or cross to the left someplace in the trunk and pass it down the left side.  You should have at least 2-3 feet of wire left when it ultimately shows up at the hood release handle.

Remove trim under the steering column. There are 3 screws and 2 plastic rivets to remove, and 2 clips attaching it to the steering column. Unplug the footwell light, cellphone speaker, and OBD2 jack to remove the trim panel.  To remove the OBD2 jack, slide the grey lock to the next detent, open the jack's lid, and push the jack through the housing.

Remove kickpanel/deadpedal assembly.  If you can find a way to snake the wire above this assembly without disassembling it and passing the wire behind it, that's fine, but I decided to take it out and run the wire behind it.

Light control module

• Remove the dash trim around the light switch.  Be careful so you don't damage your nice trim.
• Remove the 1 or 2 screws along the top of the switch, and carefully pull the assembly out. It will help if you pull the assembly and harness out several inches.  There is plenty of slack under the dash to do this.
• Use the eject lever to unplug the large connector from the Light Control Module.
• Carefully push in the 2 tabs on the sides and 1 tab on the top of the Control Module face to remove it.  There is a ribbon cable coming out of the main module and plugged into the face. Carefully unplug the ribbon.  Plug this into the new faceplate and snap the faceplate back onto the Control Module.
• Back on the large connector, slide the two blue and brown halves out the back of the connector shell.
• Find the empty contact position 49 on the brown half. Insert the front contact into this empty position, noting its orientation.
• You can either pull the long wire from the back up towards this end of the connector, or pass the wire on the end of the contact down the harness and into the dash.  Either way, tie back the wires to existing harnesses, crimp the two together and insulate, clipping off any excess wire length if you want.
• Plug the Light Control Module back into the harness.

Before buttoning everything up, put the ignition into RUN and turn on the headlights.  Press the front foglight switch (left).  Make sure they turn on and the green dash indicator lights.  Press the rear foglight switch (right).  Make sure it turns on and the yellow dash indicator lights.  Press the front fog switch again.  The rears should stay on.

If the above tests pass, reassemble everything and give yourself a hand.  You've done it.

Remember, the rear fog light is a safety device.  It is NOT a toy.  Please use it responsibly.  Maybe in future models BMW will feel that they should leave this feature in on US-spec cars like their competitors.

Notes:

• Though I don't recommend it, if you really want the rear fog to come on every time the fronts do, you could skip the new switch panel and wire this to pin 2 of the connector the front foglight relay is plugged into. This will be a pretty major pain to access, though, as you will have to figure out how to get the relay rack out.
• You could also stick a 50cent switch of some sort somewhere and just switch the light on and off with that, although that's "ghetto."
• Instead of using this as a rear fog, you could also wire up both bulbs, then connect it to the right brake light (don't know which pin this is) to act as an additional pair of brake lights, since the stock setup only lights 2 bulbs.
• As of this writing, I've only done the install on my own 5/01 production 325i Touring. This procedure should work the same way on all models listed at the top, but I can't guarantee anything until more people have successfully done this.