Hi guys and gals,
Both of my brake lights were out and after seeing this thread (
http://www.xoutpost.com/bmw-sav-foru...light-fix.html) I undertook the DIY on my own. First, I want to acknowledge Mark///M3 as I wouldn't be doing this without his thread. This was his discovery, not mine. This thread is a sort of "addendum" to his, if you will.
I am documenting this in full detail because Mark///M3's thread did not really give specific instructions. While I did not find that to be an issue, I figured a more in-depth DIY would help some first-timers. My DIY also differs in that my procedure does not require cutting any wires at all - it is entirely plug-and-play for an OEM "look."
This "mod" fixes the common tail light issue by putting the bulb socket on its own circuit (i.e. it is hard-wired opposed to being a contact connection), eliminating the possibility of corrosion causing poor contact.
NOTE: The site is not currently letting me post the pictures I took of the process - please refer to the above link for some basic pictures that will give you a visual of the kit and how it's set up.
Here it goes:
This is a DIY to permanently fix the common E53 rear brake light malfunction.
Parts needed:
-Mercedes Benz Tail Light Update Kit (one per side; kit is not sold as a pair so you will have to order TWO kits): PN 164-826-00-07 (the pair was $34.90 shipped).
Tools:
-8mm Socket
-1/4" Ratchet/Nut Driver
-A Good Set of Electrical Terminal Tools [(I have a SnapOn set and used only two tools from it: PNs SGTT2A & SGTT3A - they are available for only $11.60 each at SnapOn.com); actually, you can probably get away by using a VERY fine computer electronics flat-head screw driver].
-Cutting Instrument (to cut back any OEM electrical tape on the wiring harness; I used a razor blade but household scissors will suffice)
-Electrical Tape (Optional)
DIY:
1. Disconnect OEM Wiring Harness From Tail Light Assemblies
2. Using SnapOn SGTT3A (or similar), carefully remove white pin retainer from each electrical connector - the pins should now be exposed..
3.1 - Left: Using SnapOn SGTT3A (or similar), carefully press down on the now-exposed pin retaining tab of the Black/Brown wire and push/slide the pin out of the electrical connector. The Black/Brown wire is now free from the electrical connector.
3.2 - Right: Using SnapOn SGTT3A (or similar), carefully press down on the now-exposed pin retaining tab of the Black/Blue wire and push/slide the pin out of the electrical connector. The Black/Blue wire is now free from the electrical connector.
4. Carefully replace the white pin retainer you removed in Step 2 onto each electrical connector; it will simply "click" into place.
Quick Summary: Each connector should now be fully assembled as it came from the factory except that the Black/Brown wire will be exposed on the left and the Black/Blue wire will be exposed on the right.
5. Separate the two halves of each Mercedes connector by pressing on the tabs on either side of each connector.
6. Using SnapOn SGTT2A (or similar), carefully pry open the black pin-retaining clip on each Mercedes electrical connector (this will allow you to slide the BMW terminal connector into it).
7.1 - Left: Slide the Black/Brown wire into the Mercedes electrical connector (The Mercedes electrical connector has 3 pin locations - the Black/Brown wire slides into the middle location [i.e. next to the green wire]). You may feel the terminal "click" in. NOTE: MAKE SURE YOU SLIDE THE PIN INTO THE CONNECTOR IN THE CORRECT ORIENTATION - SLIDE IT IN VERTICALLY, NOT HORIZONTALLY. Make sure that the pin is in the correct orientation by comparing it to the green wire's pin - they should both be vertical.
7.2 - Left: Once the Black/Brown wire is "bottomed-out" in the Mercedes electrical connector, push the black pin-retaining clip that you opened in Step 6 down into place - this secures the terminals into the electrical connector, preventing them from backing out.
7.3 - Right: Repeat Steps 7.1 and 7.2 with the Black/Blue wire.
7.4 - Optional for Left and Right Sides: Use electrical tape to tape up the Black/Brown and Green wires and the Black/Blue and Green wires if you want an "OEM Look."
8. Ground each green wire onto the lower outboard headlight assembly nut/bolt (no grinding to bare metal necessary - simply unbolt the nut with an 8mm socket and ratchet, slide the round terminal connector over the naked stud, and bolt the nut back in place).
9. Connect both halves of each Mercedes electrical connector back together.
10. Insert the brake light bulb into the Mercedes bulb socket.
11. Insert Mercedes bulb/bulb socket into the tail light assembly as you normally would.
Job Done.
That's how you permanently fix your X5's rear lights without cutting a single wire and retaining the OEM finish.
This whole job took me about 2 hours. Here's a caveat; it took me 2 hours because it took me a while to figure all of this out on my own (i.e. figuring out how to disassemble the OEM electrical connectors without breaking them, looking at wiring diagrams to make sure which wires to remove/use, testing the connections, deciding on an adequate ground location, and deciding on my fit/finish). The left side, which I did first, took 1 hour and 45 minutes (because of all the detailing). Once I knew what I was doing, the right side took me no more than 15 minutes. If I had this thread to read before I embarked on the project, I could have done both sides in around 30 minutes - definitely in under 45 minutes.
I hope this thread will be useful to someone in the future.
PS. Can a moderator please PM me? The site won't allow me to upload all the pictures I've taken of this DIY.