E39 Electrical Problems Traced to Trunk Lid Harness Wire Chafing (DIY Diagnostic)

For the cross-linked record, this thread today appears to indicate that fuse #53 can blow due to the chafed wires of the trunk loom touching one another:
- E39 (1997 - 2003) > Fuse 53 keeping blowing/popping - any ideas?

For that user, red/black & gray/black were the reputed cause of his fuse #53 blowing.

From the photo below, gray/black is the license-plate light; but I'm not sure what red/black is.

Anyone know?

As i suspected, there were a couple of wires starting to break on my '03 520i.
And by the way, it's a black one!

These are the pictures I took when I examined the trunk wiring loom. I didn't take any after pix. I used Radio Shack telephone butt connectors to repair the frayed wired - clear yellow insulation. Hope this might be useful to someone.

I think a big topic of discussion is what is a reasonable way to repair this, if one does not, or cannot replace the loom? Due to the constant flexing of the wire bundle, I am not sure that either butt splices or soldering and heatshrink tubing are going to last very long. Particularly soldering...since that will make it very rigid, and likely to crack and fail quickly.

Originally Posted by bmwbmc

by the way, it's a black one!

It probably has BLUE primer!

Thanks for the pictures. Every BEFORE picture helps us identify the true cause; and every AFTER picture gives us a better idea of the best solution!

Originally Posted by abqhudson

I used Radio Shack telephone butt connectors to repair the frayed wired - clear yellow insulation.

Every picture is useful (as stated above)!

Thank you for pitching in.

I think, someday, if we all work together, we'll come up with the true cause (whether it be stretching or bending or, as recently suggested, a manufacturing defect) ... and ... more importantly ... the best solution (whether that be replacing the entire harness or various & sundry ways to patch it back up securely).

Originally Posted by 540 M-Sport

I think a big topic of discussion is what is a reasonable way to repair this

Indeed!

I know that the way "I" repaired it will not last more than a year (it's already crushed by the trunk, due to the massive addition of wires & tape & solder & heat-shrink tubing I mistakenly employed!

We need:
- A better understanding of the true cause of this common problem
and ...
- A better splicing or replacement strategy (better than mine, for sure!)

All this can be done with observation by someone more clever than I.

Unintended consequences:
The trunk open light on the dash is now off and the trunk open button in the cabin works.
But,
Neither remote key works now. Won't lock or open doors - won't open trunk.

Maybe one of my butt connectors didn't. I will work on it tomorrow and let you know what I find.

Originally Posted by abqhudson

Maybe one of my butt connectors didn't.

Thanks for the update. The good news is that you should be able to figure out, ahead of time, which (color) wires are the culprit from the information published already in this thread as to what each wire innervates (in your case, which particular one was enervated).

Although, it 'could' be a ground wire (all of which are simply plain brown).

As an aside, cn90 asked in the other thread today the following question:
- E39 (1997 - 2003) > Here is trunk open sensor?

Originally Posted by cn90

Does anyone happen to have the PN for the trunk wiring loom?

To which I replied (after reviewing this thread):

Originally Posted by bluebee

For my 2002 525i, from post #51 of the other thread, it should be this:
- 04 REPAIR WIRING SET FOR TRUNK LID 61116907260 $196.19

Note that adischino, in post #53, said he replaced his 98 528i $200 harness for $300 in parts.

Post #78 shows that others took the approach of lengthening the wires, not at the break point, but in the trunk lid itself.

Post #85 makes it all look (too) easy, based on the BMW TIS.

I know that this is an unbelievable story, so please don't respond that it's unbelievable. But this is the story - told as I believe it happened. When my remotes would not work on either key after my trunk wiring loom repair yesterday, I reread this thread.

I then checked my butted connectors by very firmly pulling the wires at either end and was able to dislodge a wire from two of them. I then proceeded to solder these two wires back together and cover with heat shrink tubing. The others all seemed solid. The remotes still would not work.

The mention by Bluebee on 6/23 that Fuse #53 in the trunk fuse box could blow if a red/black wire was frayed and broken led me to try to find this fuse. There was no such fuse in my Fuse block in the passenger side of the trunk. I decided to check all of the other fuses in this block - one 7.5 Amp fuse did not check out with my ohmmeter. Radio Shack did not have the fuse - Pep boys did not have the fuse - bought two new fuses at the BMW dealer.

On my way out to the car, I stopped to talk to my usual Service Advisor - Tony - and explained my problem. He commented that sometimes a fuse would blow and the remotes would not work - this condition was indicated by "No gas cap lock" when the doors were locked with the key. I went to the car and replaced the 7.5 Amp fuse that I thought was bad. The car beeped a couple of times - the remote would still not work. I checked and found that when I locked the doors with the key, the Gas Cap was not locked. I went back in to discuss with Tony who advised that maybe the remotes just needed to be "initialized". He proceeded to my car where he did some mumbo-jumbo press sequence in an attempt to initialize it - the remote still would not work. He looked at my fuse block and the diagram inside the compartment and I showed him the fuse I had replaced. He indicated that I needed a fuse at position 53 and I told him that there had never been a fuse in that position. Since I had purchased two new fuses I put a new one in the position that he indicated. He "initialized" the key and - the remote worked. I'm old - really old, but, I do not believe that I removed a fuse from #53 and put it back someplace else. That's my story and I'm sticking to it.

I think that everything is now back to normal and I bought Tony lunch.

Originally Posted by abqhudson

I do not believe that I removed a fuse from #53 and put it back someplace else. That's my story and I'm sticking to it.

Thanks for updating us on the, ummm ... uh ... on the 'unusual' story.

Originally Posted by abqhudson

I think that everything is now back to normal and I bought Tony lunch.

Oh sure. He gets a free lunch out of the deal ... and we don't even get a picture of Fuse #53 in situ for the thread!

Seriously though ...

We're still missing the connection point for two wires:

KNOWN LOOM WIRE CONNECTIONS:
01. Red/yellow line = 2 @ x712 -> trunk lid light (positive)
02. Red/black line = ?
03. Gray/yellow line = 3 @ 1377 -> tunk lid locking switch (open signal)
04. Brown/gray line = 2 @ x709 -> left license plate light (positive)
05. Gray/Brown line = 4 @ x311 -> zv drive (lid closed)
06. Gray/black line = 2 @ x710 -> right license plate light (positive)
07. Gray/Green -> 4 @ x311 -> zv drive rear lid (positive)
08. White/ Brown line = 3 @ x311 -> ZV to luggage compartment light
09. Brown = 1 @ x709 -> left license plate light (ground)
10. Brown = 1 @ x710 -> right license plate light (ground)
11. Brown = 5 @ x311 -> zv drive ground
12. Brown = 1 @ x1377 -> trunk lid locking switch (open signal)
13. Brown/blue line = ?
NOTE: (majority color[s])/(line color)=(pin number)@(connector number -> description

From post #101 above and your fuse-#53 experience, it can (safely?) be assumed that the red/black wire and fuse #53 and your problem are related.

That should clue us in to what the red/black wire innervates!

To the peanut gallery: What does this tell us about what the red/black wire connects to?

BTW, this response on the E46 side from G.P. Burdell may tell is WHY the bootlid wires are chafing:
- E46 (1999 - 2006) > PSA: Check Your Trunk Wire Harness

Originally Posted by G. P. Burdell

the problem is not that the wire harness is too short. The problem is the way in which the harness is designed to fold and unfold every time the trunk is opened and closed. All of that repeated flexing and exposure to heat and cold will cause the PVC wire insulation to crack and the strands of copper wire to break. Tension on the harness has nothing to do with it.

FWIW, I consider it a sign of tribal 'success' that we were able to predict exactly which wires were broken based purely on the symptoms a user reported over in this recent thread:
- E39 (1997 - 2003) > License plate bulb wiring help



PS: Notice, yet again, the blue-BMW trunk wiring of death strikes again against our BLUE painted BMWs!

Hey - Is this a great forum or what??? Thanks to all.

Thanks for all the info on this topic, just found and fixed 3 broken wires in 30 minuted instead of 30 days because of this thread. ohh and my E39 is black.

Good news Bluebee! I have a TITANIUM SILVER 98 M62 with chaffed wires at the deck lid grommet.
Started with apparent actuator failure. Replaced actuator but no improvement. After several minutes of chin rubbing pulled down the grommet and sure enough: 2 chaffed wires. Repaired with crimp connectors & shrink tube, original actuator works fine.
Now have 'check rear lights' on the dash, but no lights are out. Probably same problem, I'll look this weekend.

Bugger... three broken wires!Grey/green, brown, and the mysterious red/black. Tried to remove the snorkel tube from main body so I could slide it past the breaks for a nice clean repair but it won't disengage. I wonder where it it secure near the rear seat? I may go to a local wrecking yard and see if the have a good harness with no breaks but I would still have to dis-engage the harness from the body; any ideas? This repair is some-what minor but good gawd doesn't BMW hire engineers with degrees?!!! So what does the red/black wire connect to? PS Thanks Bluebee for all the work you do on this forum. (And my car is a '02 525i in Steel Blue!)

Originally Posted by fortunateson

Tried to remove the snorkel tube from main body so I could slide it past the breaks for a nice clean repair but it won't disengage. I wonder where it it secure near the rear seat?

That's interesting. Most people pull the snorkel down from the trunk lid side; so I can't tell you how to remove it from the body side. Let us know (with pictures if you can) how that works out.

If others have removed the snorkel from the body side, please let us know what the procedure is, so all benefit.

Originally Posted by fortunateson

I would still have to dis-engage the harness from the body; any ideas?

I think it was G.P. Burdell, who, on his E46, did just that. He removed the harness and repaired it off the car. Then re-installed it. His DIY is referenced. If you go that route, please SNAP PICTURES as I haven't found yet an E39 who removed the $200 harness.

Originally Posted by fortunateson

what does the red/black wire connect to?

Good question!

If anyone knows what the red/black wire connects to, please let us know!

Originally Posted by fortunateson

my car is a '02 525i in Steel Blue!

Mine too! Those blue B's sure do seem to be badly afflicted by this trunk-loom BMW design flaw!

Didn't call the dealer yet but the wrecking yard guy said that the trunk harness could only be separated from the main harness but cutting it. I told him that BMW lists a trunk harness as a separate part but he insisted that there is no plug/ connector to disengage and that I would have to splice the new harness into the main harness. If that's true the why would anyone pay $200 to splice when you may as well repair the original? I like the idea of wrapping all the wires with friction tape (NOT electrical tape) in an effort to build in some rigidity to all the wires in an attempt to prevent a repeat of this anoying problem. RED / BLACK, RED/ BLACK?!!! Aren't these colours associated with Lucifer and his boys?

Originally Posted by fortunateson

I told him that BMW lists a trunk harness as a separate part but he insisted that there is no plug/ connector to disengage

It is definitely listed as a separate harness; so, I 'assume' there is a connection.

The G.P. Burdell DIY might have that connection described.

As for the red/black; I'm not sure why the EE's out there can't tell us where it goes yet!

common issue
happened to me as well ... crap

http://forums.bimmerforums.com/forum....php?t=1441236

Originally Posted by champaign777

common issue

Originally Posted by champaign777

happened to me as well ... crap

http://forums.bimmerforums.com/forum/showthread.php?t=1441236

On the '01 or the '03?

Just for the record, my horrid wiring loom repair job is looking more and more embarrassingly bad.

Every time I open the trunk, I shudder at what it is starting to look like; but at least all the buttons work to open the trunk!

[quote=bluebee;6313654]Just for the record, my horrid wiring loom repair job is looking more and more like what the BMW engineers designed, over time.

Every time I open the trunk, I shudder at what it is starting to look like; but at least all the buttons work to open the trunk!

[/quote]

OMG!!!!! There must be a way to do it "nicer"!!!!

Had this issue on my silver 99 528I with 110k, My roommates blue 01 530I with 130k, did not have this.

Originally Posted by doru

[quote=bluebee;6313654]Just for the record, my horrid wiring loom repair job is looking more and more like what the BMW engineers designed, over time.

Every time I open the trunk, I shudder at what it is starting to look like; but at least all the buttons work to open the trunk!

OMG!!!!! There must be a way to do it "nicer"!!!![/QUOTE]

did you do it in the dark????

Called the dealer just now. There is not a junction where the trunk harness plugs into the main harness. The sub hareness that you can purchase needs to be spliced and soldered in at nearly the same location where the breaks occur. (why bother; repair the original one.) There is no way to dis-connect the bellows/ snorkel in order to slide it past they are so you can make an elegant repair and not have to cut the rubber tube. I'm thinking that I'll go down to the local wrecking yard and see where the harness sits near the package shelf. I may be able to determine if the bellow/ snorkel could be detatched further up-stream. I may find a section of the harness that I could buy and replace it within the cabin itself rather than hacking up the bellow/ snorkel. Service tech says that this is a very common problem and happens on 3 series as well. Could the red/black (El Diablo) wire be for the release just above the lisence plate?