tonypll

i stumbles across this forum whilst looking for a solution to my boot lid not opening and licence plare lights out and 3rd brake light not working.
many thanks to all for the posts that made my life so much easier as to the problem fix, i too had 3 wires broken and repaired them with very little time and effort!
it cost me nothing as all the things i needed were already in my toolbox...

tony in yorkshire uk.

AMGAffalterbach

Glad it helped! (Not that I was a contributor lol) Welcome to the forums Tony!

swindon_taxi

different area but found a severed BROWN wire and now all sorted

Thanks

Why is it always a brown wire?

swindon_taxi

Thanks
Found the BROWN wire and hay presto all sorted now

mbnnrh

Post helped me solve this problem. It was brown wire for me as well.

I wrapped the entire section of wire in the area of the repair with electrical tape. Then, I reattached to the swing arm with a zip tie. However, I left some slack in the zip tie so the wires can move freely without getting severed again.

Now, I must repair two other issues. 1) The Brake/Stop Light Switch issue and 2) I have received the temperature stop car immediately message twice in the past week.

N_Jay

Just happened today.


We are away on vacation and almost had golf clubs locked in the trunk.
This is the first time I needed to use the trunk key and of course set of the alarm.


Hopefully it is the simple fix like everyone else.

AMGAffalterbach

^I had that when my battery died, nothing worked except for the alarm apparently and when it didn't recognize my key fob I ended up setting off the alarm a few times in the process of getting the car jumped. A bit embarrassing lol

N_Jay

Took me about an hour going slow.
I had trouble figuring out all the pieces that need to come out to loosen the side panel. There was even one bolt.


I used a butt connector, covered it with heat shrink, then wrapped that bundle about 2 inches in and out of the loom.
Then started past the loom and wrapped the outside to keep the loom end from moving.


Don't go crazy as it still has to fit under the hinge cover.

skipsantos

Just bought a 2008 E350 and three days later - left and right license plate lights and third brake light go out along with trunk switch. This fix was dead on. It took more time logging in and searching for the fix than the actual fix itself. Thanks for the guidance.

ezermid

Thank you very much, first i thought that its not real and it was other problem but i want to thank you and to all the forum that gives solves to problems that we never find without the internet!!!!!!!

aguison

This forum saved the day! I had the identical problems reported in the previous posts - yesterday after stowing my laptop in the trunk after work, when I start the car, there's a message on the center gauge "3rd brake lamp", then would change to "license plate light left", then change to "license plate light right" and kept rotating between the 3 messages. When I got home, I tried to pop the trunk with my remote, it wouldn't open. Then tried opening trunk with the driver door switch, wouldn't open.

Then I googled "3rd brake lamp" and found the posts on this forum. It was exactly what was described - for some strange reason, the brown wire which is part of a bundle of wires attached to the left hinge of the trunk with a plastic tie was "cut". I don't know how, but suspect the black plastic part which covers the left hinge hits the wire as the trunk is opened and closed and over time, it's like bending a piece of wire up and down repeatedly until it breaks.

The way I repaired mine was strip both ends of the brown wire about 3/8", twist them together and solder them. Then just use electrical tape to protect the connection. I cut the plastic tie which supported the wire bundle. Next I used a black 3/8" plastic split loom and wrapped it around the entire wire bundle and secured the wires with a new plastic tie.

Notes:
1. When you remove the left panel cover inside the trunk, you will have to remove 2 plastic fasteners on the side and 2 fasteners on the bottom.
2. I found that I had to remove the plastic panel on the rear as well to make it easier to remove the left panel. There are 6 plastic fasteners to remove.
3. All fasteners were reusable.
4. When you reconnect the brown wire, the car will start honking the alarm. Relax, just use your key to turn it off.
5. Test the car before putting everything back. On mine, it still displayed the error message. I popped the trunk and restarted the car and that somehow reset it.
6. On mine the brown wire severed INSIDE the plastic piece which covered the hinge. I had to remove the plastic piece to get at the brown wire.

BenzboyW210

Thank you sir! Had the same issue, checked fuses and nothing wrong there. Then Googled the issue and found this thread. Pulled the panel and the larger gauge brown wire (ground?) was severed exactly where you stated. I inspected the rest of the wiring bundle (which should be encased given the physical mechanical movement around it) and it was fine.

I had by chance just purchased a set of both heat shrink wrapping and butt connectors, so I was well equipped to fix.

15 minutes later, all is well. Definitely seems to be a common issue with W211's.

Cheers.

Bomb_Bay

Just adding to all the notes of thanks for this post. Wire severed this morning, my garage knew exactly what it was and told me over the phone. A minute to find this post and 30 mins to fix with 2 bullet connectors and a joiner all wrapped with insulating tape.

Brown wire, down where the plastic tubing finished. Figured out the fixing OK just life the centre tab and they come out very easily.

Thanks again

georges66

Thank you hbamark for the solution. One brown wire was cut, so I stripped both ends and crimped a connector to them. Problem solved. The hardest part was prying the side wall carpet without damaging it. Saved a few hundred bucks.

marathonrunner

I too want to express my sincere thanks to hbamark for the post. Although getting the side of the trunk liner wasn't as easy as it should have been, I actually had 3 wires that were broken. 2 of which actually broke in 2 places, so there were 3" to 4" pieces laying in the floor of the trunk. Plus, a 4th wire was getting ready to break. Unbelievable that happened. Thank you, thank you, thank you. Saved me much heartache and time & trouble.

Afarsian

Brown wire on mine. It brakes right at the tube, i think you should reconsider plastic tube to something softer.

N_Jay

They needed to bring the tub up further so the bending is all in the tube and not at the edge.
They probably should have also used a thinner stranded more flexible type of wire.

Dandaco

Had the same problem. Followed the instructions. Brown wire was split/broke. An easy fix with help from this post. Thank you sooooooo much!!!!!!

Sugar_Mouth

Same issue here.




The wire was hidden under wrap so you may have to pull back the wrap to find it.

black_e63

This thread is gold, Jerry, gold. I had the broken brown wire as well, and now I am back to "tip-top" shape. Thank you OP and this community!

tocky11

OMG.. this was incredibly easy to repair, even a women (me) can do it - very good instructions - took me about 20 minutes to repair! Thank you so much!

philipvrl

And yet another thanks for this post & solution.
Indeed, the brown wire as well... MB most probably made an error in selecting a wire which is not flexible enough..
Txs !!

dr2828

Thank you so very much. I saved hundreds of $$ fixing this myself. and I'm not the greatest mechanic but followed your directions slowly and carefully. all is well, used some elect tape, patience, heat-shrink tubing, and now ready to go. My local MB mechanic( not dealer) was closed, called a few auto-electric places and most said, "leave it w us and we'll call you, should take most of a day and regular 'hrly rate' til we figure out what's wrong!" only appts were 2-3 days from now. I appreciate all you people's fine work and time. it was my brown wire as well.
alan

LakeIce

I also have no power to my trunk and the key also doesn't open manually and the back seat can't come off unless you get to the trunk I'm kinda stuck here any suggestions?

N_Jay

The key is a little tricky.


I forget which way you turn it, but the trick is to;
1) TURN THE KEY ALL THE WAY.
2) HOLD THE KEY TURNED
3) PULL THE TRUNK RELEASE HANDLE


Try one way first and then the other.