My BMW 535xi Touring is a 2010 model manufactured in March, 2009. Almost 6 years old with 120,000km. Last summer my remote locking failed – and it wasn’t the diversity antenna module under the rear spoiler, so I suspected wiring issues. I took it to the dealer to have them check it out – and they charged me about $500 to re-splice about 6 broken wires on the right side hinge harness. Since they didn’t insert a repair section – I was sure that this problem was going to reappear, and from what I’ve learned on the forums, I decided to try out the Sencom repair harness kits – with silicone insulated wire for better protection from repeated flexing, particularly at low temperatures.
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| Melted rear window defroster ground wire (far left) and cracked tailgate lights / locks ground (far right) |
This fall – at the onset of winter – I noticed my rear window defroster wasn’t working. I suspected a broken wire in the defroster circuit, so I knew it was time to get at the harness repairs.
I ordered the kits through Autoteilemann.de – very quick and easy and the DHL shipping they quoted included all the taxes, duties and brokerage charges. It took about a week to receive the kits. I ordered 3 to be able to do a complete harness replacement – left and right. There is the kit for the right side harness, and 2 kits for the left side harness – one for the electrical wiring, and one for the antenna cable and windshield wiper fluid tubing.
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| Left side SenCom Kits Antenna Cable and Washer Tubing - P/N ANT0612 (left) and Tailgate Harness P/N 2016062 (Right) |
The kits came with everything required for installation – all the butt crimp connectors, heat shrink tubing where required, new terminals for the defrost attachments on the rear window, terminals and terminal housings for the antenna cable splice and diversity antenna amplifier attachments, washer fluid tubing and barbed tubing splice fitting, and the rubber boots for the tailgate wiring pass through on the left and right sides of the rear window – pre-installed on the wiring loom.
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| Crimps, Antenna Connectors and Shells, Heat Shrink, Tubing Connector supplied by SenCom with the Left side kits |
In preparation for the job – I only had one tool which I needed to add – a crimper for the very small insulated crimp connections. I picked this up at an electronics supply store. Otherwise, for tools, I used a Klein stranded wire stripper (red handled) for all the wire stripping, and an insulated channel lock multipurpose crimper for the standard red, blue and yellow insulated butt crimp connectors.
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| Crimper for very small gauge crimps (Top left), Klein Wire Stripper (Top right), Channel Lock Crimper for standard Red, Blue, Yellow Crimps (Bottom) |
I heat shrunk all the connections under the rear spoiler around the diversity antenna amplifier to ensure no moisture would get at any of the connections, so the heat gun came in handy there. When doing both sides – you’ll have about 120 wires to strip over the job – so make sure your stripping tool is sharp and in good condition.
I followed the Sencom video on Youtube to guide me through the process – very thorough. Here's a good tip - when the instructions come up in the Youtube video in german text - use your iPhone or Android Google Translate App to translate this text immediately - I was really surprised at how well this worked. The translation was never perfect, but you could get the idea fairly quickly.
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| Google Translate App is your friend with the German language text in the SenCom video |
Start by opening the tailgate and opening the window glass first, then by disconnecting the battery negative post. I waited for the car to go to sleep mode prior to disconnecting the battery – about 10 or 15 minutes. I placed some small rags in the catch for both the tailgate and the window to prevent them from latching during the job.
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| Rags under the window and tailgate latches will help keep you moving - so you don't have to manually unlatch these if you accidently let them close. You'll be opening and closing the glass and tailgate many times during this repair, especially if you're doing both sides. |
I started on the right side – removing all the trim panels per the Sencom video exposing the harness between the tailgate and the windows. I also made sure to let the car warm up in the garage overnight - so that the plastic and wiring wouldn't be cold and brittle.
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| A trim removal tool will help keep you from breaking the plastic. |
When it came time to remove the curved black wiring supports in the hinge – I used a piece of wire coat hanger to push the pins out of the plastic clips retaining the wiring supports – makes removing these clips much easier.
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| Mini screwdriver worked on the outside hinges to remove the locking pin of the clip holding the black wiring guides |
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| A short piece of wire coat hanger was flexible enough to get at the inside hinge pins - where the screwdriver couldn't access |
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| The trim removal tool was perfect for removing the clips once the locking pin was pushed out |
Removing the wiring guides was a bit tricky - using a rag to help protect the paint was a good idea when coaxing the wiring guides out from inbetween the tailgate and glass hinges. It can be done without loosening the bolts on the metal hinges.
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| Removing the black wiring harness guides - protect paint with a shop rag |
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| Plastic storage container for keeping trim hardware in the order of removal - makes replacing the hardware much easier as you put everything back together in reverse order |
Cut the old harness, splice in the new harness on the right side at the tailgate – then remove the speaker in the roof just ahead of the window hinges to access the harness on the inside of the car.
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| Carefully separate the OEM cable boot from the cable wrapping, and slide up and out of the way |
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| Cut the harness - 10cm / 4" of free cable gives you lots of space to perform the splices |
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| I upgraded the larger gauge splices (blue size) with heat shrinkable crimp connecters that I had on hand |
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| All cables crimped on the right side talegate harness - and waiting to test. Note the number labels on some of the wires to uniquely identify the conductors in the SenCom harness that have the same gauge and color |
Pull the old harness through the hinge area, cut the old harness out leaving at least 6” of the old harness to give you space to make connections in the speaker area. Pull the new harness through the wire boot underneath the speaker area, and make all the splices in the speaker area.
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| Both right side SenCom harnesses pulled through the body cable boot up from behind the inside rear speaker - I used electrical tape on the SenCom harness to make pulling the harness through the boot go easier. Then I removed the electrical tape to perform the splicing |
Then go on to do the same for the harness running under the rear spoiler in the diversity antenna amplifier area. The connections under the spoiler are where I ran into a slight issue – one of the wires is brown with a very thin blue line – I mistook it as a ground wire and didn’t track it in my splicing. I had to go back, cut the splice I had done inside the car to identify this wire to the other end of the harness in the diversity antenna area.
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| Right hand side cable splicing in the speaker opening. |
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| Harness Splicing Complete on the Right Side |
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| A good trick for working with the factory harnesses after you've removed the adhesive tape wrap - is to remove all the residual gum from the wires with Goo Gone before starting the splicing. This will help keep your hands clean during the crimping. |
All the ground wires – straight brown with no stripes in the factory harness – can connect to any other brown wire of the same gauge in the harnesses – you don’t need to match them to the same ground wire exactly. Otherwise – obviously – all the colored wires need to be connected correctly. The Sencom harness has a series of wires of the correct gauges but some wires are duplicates and you’ll need to track the duplicate colored wires with a continuity meter – so that you can identify them individually and track the connections. To get this straight – for each harness I cut and spliced – I wrote out a list of every wire – primary color and stripe color, and matched it with a particular color in the Sencom repair kit – e.g. Red wire no. 1, Red wire no. 2., White wire no. 1., White wire no. 2. Then when I made the matching connections at the other end of the harness – it was simple to get everything matched up correctly.
With the 2 harnesses completed on the right side – I moved over to the left side and followed the same method for the tailgate wiring harness, then did the diversity antenna cable / washer fluid circuit / defroster ground wire harness. This is where I found that my defroster ground wire had completely melted through.
To splice the antenna cable – Sencom provides you with a matching pair of male and female OEM style RF connectors – which were fairly straightforward to install. You have to strip the antenna cable in three stages – the outer cable insulation, the inner shield wire, and then the signal conductor insulation. I judged the strips and cuts based on the old connector – and on the female conductor, you need to crimp on a special, tiny, female signal conductor pin. A bit tricky. I managed to get this right – eventually proven by good radio reception and lots of channels when I got everything back together and tested.
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| Preparing the OEM side Antenna cable for crimping the RF connector |
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| Female terminal crimped to the center core signal wire |
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| Shield Body Crimped over the female terminal / ready for the plastic terminal housing |
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| Female RF Connector with Female Signal Conductor - Gold Color |
Once everything was reconnected – and prior to reinstalling any wire guides or trim panels, I reconnected the battery and tested everything. Signals, brake lights, parking lights, reverse lights, license plate lights, defroster function, radio, central locking, cargo cover release, tailgate release, window release. Everything worked perfectly the first try. No fuses blown.
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| Test all functions prior to re-installing the rear spoiler, or replacing any of the harnesses or trims. |
So then – I disconnected the battery again just to avoid any possibility of a short circuit while replacing wires, and tucked away the wires and reinstalled the trim. The wire guides next to the hinges were a bit tricky to get back together, but I got everything clipped together and tightened the guides with a set of pliers so they would hold together firmly. I touched up any small scratches on these guides with a black Sharpie, so I looked like new when it was all back together.
I pulled the new harness through the boots in the roof just forward of the hinges so that there would not be too much slack in the harnesses ahead of the hinge wire guides – so the harness would not be able to be pinched in the hinges. Then I double checked the opening and closing of the tailgate, window and made sure the harnesses were moving freely without pinching. Then – tucked the splices up underneath the speaker openings, replace the speakers and trims, and reconnected the battery.
So – with the repair completed, I noticed that my remote locking / unlocking range became much better. I was down to being able to lock or unlock the car within only about 10’ of the tailgate. If I was at the front of the car, I couldn’t even unlock it. The broken ground connection for the defroster circuit may have been the cause of the lack of range of the remote locking circuit.
Conclusion
Radio reception was excellent, with lots of channels and maybe more channels than I had before (better reception?). It also seemed like comfort access was working a little bit better as well.
Repair time – about 12 hours total. 4 hours the first day, and 8 hours straight the second day from start to finish. Hopefully I won’t have to go back into this for the entire time that I own this car. This is clearly a design deficiency, hopefully BMW corrects this in future variants it builds with tailgates. 12 hours is a lot of time to spend on this – but I love the car and hope to keep it for a while (hopefully until BMW imports a future 5 series touring to North America….)
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| SenCom Wiring Harness Kits |
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| Right and Left Side Wiring Harness Part Numbers |
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| Left Side Antenna Cable Part Number |
4 Year Update
I've been running this repair for just over 4 years now - and it's been solid. No futher issues, no problems with any of the tailgate lighting or functions. Rear window release and defrost still working great. All good. Impressed with the quality of these kits.
Sources and Links
The Sencom kits were a bit expensive to have shipped from Germany with duties, taxes, brokerage, etc. but the kits are excellent quality. I can confirm the kits work fine with North American vehicles (535xi Touring LCI e61) with one spare conductor on the right hand side, and one spare antenna cable on the left hand side. Thanks to Sencom for supporting us with a quality repair kit and an excellent instruction video. Thanks to everyone on the various BMW forums for your support, I've gotten lots of good feedback on this post and I appreciate it.
Sencom 2016061 on eBay
Sencom 2016062 on eBay
Sencom Ant0612 on eBay.
