If you have a 2002-2005 sedan and your taillight bulb-out indicator keeps coming on even though you KNOW all the bulbs are good, then this DIY is for you.
Background: When you first turn on the car, it will self-test the light bulbs by sending a brief pulse to all the bulbs. If it finds a bulb whose resistance is too high, it thinks that bulb is burnt out and will illuminate the bulb-out indicator on the dashboard. However, in the 2002-2005 E46 sedan, the single small ground wire in the taillight wiring harness is inadequate. Over time, the resistance in the ground wire's connector inside the wiring harness will increase, leading to erratic bulb-out indcators and, in the worst cases, melting damage to the wiring harness.
In this DIY, we'll add an additional ground wire which will remedy this problem.
This DIY is intended to supplement the BMW TSB , "Poor Connection at Rear Lamp Connector" which is applicable to 2002-2005 (facelift) sedans. This DIY is not intended to completely replace that TSB. Please review and/or print:
http://www.bmwtis.com/tsb/bulletins/...p/B630306g.htm
I'll assume we're fixing it BEFORE anything melts - otherwise, you'll have a few extra steps which are covered in the TSB but not in this DIY.
STEP ONE: Acquire your parts
PARTS: The parts are inexpensive from the dealership - around $10 if you only need to add the new ground wires, or slightly more if you need to replace melted wiring harnesses.
NOTE: The note in the TSB regarding the number of parts is misleading. The part quantities listed in the TSB are a mix-up of adding the ground wire to both taillights, and replacing the 8-pin harness on one taillight.
I didn't have to replace the wiring harness, so here's my parts list:
I purchased (clockwise starting from top left):
(6) of 61 13 1 387 144 flat contact for comb-type connectors
(2) of 61 13 1 393 718 comb-type connector (housing) 3-pin
(1) of 61 13 1 387 150 comb-type connector (contact strip)
(2) of 12 52 1 433 217 blade contact SLK 2.8
I already had the two other blade connectors and some wire. If you need to buy the blade connectors, then get:
(2) of 07 11 9 975 531 flat plug-in sleeve 4.8-2.5
STEP TWO: Get everything ready
Twist or clip the connectors off of the little sprues to which they come attached. Cut up the comb-type connector so that you have two three-prong pieces, as shown below. You'll have a lot left over.
Cut your wire into four 3-inch segments. Shown below, I had two short segments and two longer segments; I eventually decided to do all four short segments, as you'll see later. Strip off about a quarter-inch of insulation from each end of the wire.
Lay out all your parts to make sure you have everything:
STEP THREE: Assemble the new parts.
Crimp the connectors onto the wires. I used a very small needle-nose pliers. One crimp goes on the bare wire and one crimp goes on the insulation. I did it wrong on several of mine before I realized my error:
IMPORTANT: Don't just go crimping stuff all over the place. Make sure you make your wire assemblies as described in the TSB and as shown in the third photo:
- Each of your four wires should have a "61 13 1 387 144 flat contact for comb-type connector" on one end.
- You'll have two of "61 13 1 387 144 flat contact for comb-type connector" left over
- Two wires should have a "12 52 1 433 217 blade contact SLK 2.8" on the other end
- The other two wires should have a "07 11 9 975 531 flat plug-in sleeve 4.8-2.5" (or equivalent) on the other end.
STEP FOUR: Tap into the car
Open the trunk. Twist the little knob near the inside-trunk lights, and the bulb carrier will come out. Unplug the wiring harness.
Now comes the biggest hassle:
Get the ground wire out of the wiring harness. As shown in the photo, you'll need to prise up the plastic clip and simultaneously pull out the wire or push out the connector on the end of the wire. An extra hand helps a lot.
(If you're replacing a melted wiring harness, you'll need to push ALL the wires out of the wiring harness - that's 8x the hassle)
Clip off the connector from the end of the ground wire; discard. Strip a quarter-inch of insulation and crimp on one of your remaining 61 13 1 387 144 flat contact for comb-type connectors. Plug it onto one prong of the 3-pin comb connectors that you created.
STEP FIVE: Final Assembly
Plug the other two wire assemblies onto the other two pins of the 3-pin comb connector. (sorry, the text on this photo is misleading, I forgot that we replaced that connector with a different connector)
Insert the 3-pin comb connector into the housing.
Insert the 12 52 1 433 217 blade contact SLK 2.8 (crimped to the other end of a wire segment) into the ground hole of the wiring harness.
Plug the 07 11 9 975 531 flat plug-in sleeve onto the large lug on the bulb carrier (pictured on the TSB). Plug the wiring harness back into the bulb carrier. Tuck away the 3-pin comb connector & housing, and reassemble the bulb carrier into the lens.
Done!
Repeat for the other side.
Excellent work!
E36 DIYs: Air Pump | Vent Gauge | E46 Armrest | SmarTire TPMS
E46 DIYs: Hella TPMS | Aftermarket Horns | Window Regulator Notes | Trunk Wire Harness | Trunk 12V Socket
(6) of 61 13 1 387 144 flat contact for comb-type connectors
(2) of 61 13 1 393 718 comb-type connector ([COLOR=blue ! important][COLOR=blue ! important]housing[/COLOR][/COLOR]) 3-pin
(1) of 61 13 1 387 150 comb-type connector (contact strip)
(2) of 12 52 1 433 217 blade contact SLK 2.8
So these are the BMW part #'s? I need to pick them up tomorrow and do this set up.
Yes, however read the TSB and the DIY post as you may not need all the parts depending upon what you want to do. The TSB parts list provides enough parts to fix the problem two different ways depending on whether the harness/plug is burned/melted or whether their is only ground wire (brown) connection corrosion or darkening of the wire blade or connector end. Of course if you buy them all, you are ready for any situation you may find.
Nathan, First thanks for posting these exellent instructions.
I'm a novice at fixing electrical stuff, do I need to unplug the battery before starting this so I don't electricute myself?
If your wiring harness is not melted, it's not necessary to disconnect the battery. You'll only be working with the ground wire, which is not hot.
If I recall correctly, there will still be power to one of the pins of the wiring harness - the one that lights up the interior trunk lights. But you won't be working with that pin if you're only adding the additional ground.
If you're replacing melted plastic wiring harness, and you have to remove all the pins from the old/melted plastic part, then it's a good idea to disconnect the battery, so that single hot wire doesn't touch anything else. I don't really cover that in my instructions above.
Anyway, if it makes you feel safer to disconnect the battery, it's never a BAD idea to disconnect it while working on electrical things.
I ended up not disconnecting it, figured I'd take my chances, BUT turns out the wiring harness does need replacement.
I thought I could get away with it because it was a small portion of the pin that looked like was corroded, but after the corroded pin fell out on it's own I figured the new one won't hold either. Tried the new one and it falls out too ((.
Unfortunately all parts dealers near me are closed on Sat. so I'm grounded until Monday . I'll take out the battery on Monday when I go to remove all the pins, at least it's 7x the hassle at this point not 8 .
BTW did you experience any of the wires coming out of the metal thingies after you crimped them? I followed the directions to make sure I crimped them on the casing, but some of them are still not holding too well. I used pliers, I have a crimping tool but it was driving me nuts, might have to recrimp all of them on Monday.
The crimps should hold against pulling out. Tug each one after crimping to make sure they're solid. One vendor recommends testing with at least 10 pounds of pull.
You need an open-barrel crimper for these terminals. The tools found at hardware stores are usually for insulated, closed-barrel terminals. A crimper for open-barrel terminals curls the tabs down over the bare wire for a solid crimp.
You can get an open-barrel crimper that does a decent job for about $30 from places like Summit Racing, but if you're going to be doing a LOT of crimping on this and various other electrical projects, then you should invest in a good ratcheting crimper with interchangeable dies. I have been very satisfied with my Paladin Tools crimper.
Last edited by G. P. Burdell; 08-01-2009 at 02:49 PM.
E36 DIYs: Air Pump | Vent Gauge | E46 Armrest | SmarTire TPMS
E46 DIYs: Hella TPMS | Aftermarket Horns | Window Regulator Notes | Trunk Wire Harness | Trunk 12V Socket
Ok thanks! I'll play around with it again I think I'll definitely have to recrimp them better as one of them detached without any force when I was trying to attach them to the metal combs, they are a bit frustrating.
E36 DIYs: Air Pump | Vent Gauge | E46 Armrest | SmarTire TPMS
E46 DIYs: Hella TPMS | Aftermarket Horns | Window Regulator Notes | Trunk Wire Harness | Trunk 12V Socket
True, I haver the crimper tool at my disposal. At least it looks almost the same as the one in the picture, but knowing how to use it properly is a whole different story! lol I just need some practice.
Thanks for this great DIY post! This helped me a lot in my DIY repair. There is an even easier way though... In your last photo, the ground wire you instruct to place back into the original 8 pin connector is not needed. Once you pop the brown ground wire out of the 8 pin connector, simply remove any bad part of the wire, then add 4 more inches of wire to it, and then connect that to the ground bar tab on the tail light assembly. You see, the metal bar, with the tab you connect to, in the tail light assembly, is the same bar the coresponding pin in the 8 pin connector, connects to. An ohms check from the ground pin in the 8 pin connector, that's attached to the tail light assembly, to the tab in the tail light assembly you connect the ground wire to, will verify this. Your directions have you connecting two wires to the same place, only at two different locations. One connection is all that is needed. This way, no special BMW parts needed, just some watertight electrical connections, and a small piece of (same or larger guage) wire.
Thanks Again! Your post helped me fix mine, and my electrical skills found a better way.
Thanks for the tip. That's definitely the easier way. My goal was to implement the service bulletin exactly as BMW issued - but I don't know if I would do it that way again
Excellent write up. I had the same issue on my 2003 BMW325i. The BMW dealer wanted $198 dollars to fix it or he offered to sell me the parts kit. I went to the parts department and the guy said it is a common problem and I sell these kits like hot cakes. He then brought out 8 crimped wires and the plastic wiring harness and said that it would cost me $35. I told him that only one of the wires is corroded and I only need one of the wires since the plastic harness is fine. He then said take one at no charge. I went to radio shack and bought a packet of 1/4 inch clips and I followed your instructions to replaced the corroded wire and attach it to the ground plate. After crimping the clip and connecting it, the warning light disappeared and I only paid $1.99 for the clips from radio shack. The whole process took me 10 minutes and the BMW dealer wanted to to charge me 1 1/2 hours labor- what a rip off. Thanks again for all your help!!
Nathan, thanks so much for posting this DIY. I followed it on both sides, TWICE! But obviously I didn't read the first sentence closely enough where you said "even though you KNOW all the bulbs are good."
After doing this fix twice first with 18 gauge wire then 16-gauge wire, I still had a bulb-out indicator lamp. Then I found one of my tail lamps had a failing filament even though it would still light up. But I'm still glad I did it because my ground wires on both sides had corroded connectors at the end. The left one had melted a small hole in the plastic socket.
NathanCarter,
Thanks for the great writeup. I just finished this. I had the warning light on for a good 6 months before I finally got the parts and gave this a try and it worked like a champ!
I would add that in Step 4 to get the ground wire out my wife used a pair of pliers while I held the catch open with a small screw driver. I couldn't get a push with anything else.
Glad it was helpful, thanks for the acknowledgement
E8F68B5D-F951-99A0-B310-1113401C9599
1.02.28
Nathan--thanks for this...great write up! The SIB is a bit confusing on what to plug into what. The pictures cleared things up
I completed the TSB for this and all the lights work now, but for some reason the obc still says my rear lights are out.
Did I miss something here?
Noticed someone brought up an issue of a fail filament. What is that exactly?
Last edited by projeks; 12-23-2010 at 02:49 PM.
Alright, checked it and will need better bulbs.
Thanks
I am unable to link to the TSB mentioned above. Does anyone know if there is an updated link available?
thanks!
Once again this forum comes up trumps, thanks to people like you Nathan. Thank you. Did this today, changed the two wiring harnesses out as well. Fiddly, time-consuming, but ultimately worthwhile. Took a chair outside, parked it at the rear of my car, sat in the sun and fiddled. Worked a treat. Just one thing - if you're changing the harnesses, no need to disconnect the battery. Just pull fuse #51 which will disable the one live wire back there in the trunk (interior trunk lights).
Last edited by 2bms; 02-18-2011 at 06:59 PM.
I've been having this problem, but I don't have a dealer close by to get the parts and don't want to order the kits online through Pelican Parts for $40. So I'm thinking about trying this solution.
But Please correct me if I'm wrong, it sounds like you can just remove, extended, and connect the ground wire to the metal bar. Problem solved? Any potential risk in doing this way? Also, Thanks for all the info OP. Didn't know about the TSP until I started having the problem.
Never trust a man with a pig farm
That will almost certainly work, IF the grounding problem hasn't gotten so bad as to melt the wiring harness.
Please use a proper method of connecting the wires - solder and heat-shrink, or crimp connectors. Don't just twist them together and wrap it with electrical tape, you're not Fred Sanford.
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