[vilord]

Hey y'all.
I'm going over the niggles in my new wagon, and after swapping the reverse light and seeing no improvement, I discovered that the tailgate harness is damaged at the hinge point.

Beyond repairing the broken wires, any suggestions to keep it from happening again? Wrap it with electrical tape? Or, friction tape? Or...

Thanks!

[nsjames]

are they damaged from the harness being pinched, or damaged from the wires flexing and breaking?

if pinched, they were not secured properly.
if flexed until broken, buy a high quality silicone jacketed wire to repair with. Splice on either side of the hinge line. It will last longer.

[vilord]

I guess I'll find out when I pull it apart, but either way, thanks! Perfect response

[slupie]

Originally Posted by vilord

Hey y'all.
I'm going over the niggles in my new wagon, and after swapping the reverse light and seeing no improvement, I discovered that the tailgate harness is damaged at the hinge point.

Beyond repairing the broken wires, any suggestions to keep it from happening again? Wrap it with electrical tape? Or, friction tape? Or...

Thanks!

Good luck, I have fixed mine 4 times already and same thing happens. The modern insulation is soy based and becomes brittle in the cold and then cracks. I'm about to do it for the fifth time and hopefully the Igus high flex cable will last longer. This is what I bought https://www.automationdirect.com/adc...ed/cf5-07-04-1

This is what keeps happening

https://www.e90post.com/forums/showthread.php?t=928522

[vilord]

This is fine

[Efthreeoh]

Originally Posted by slupie

Good luck, I have fixed mine 4 times already and same thing happens. The modern insulation is soy based and becomes brittle in the cold and then cracks. I'm about to do it for the fifth time and hopefully the Igus high flex cable will last longer. This is what I bought https://www.automationdirect.com/adc...ed/cf5-07-04-1

This is what keeps happening

https://www.e90post.com/forums/showthread.php?t=928522

Thanks for posting this. I have an upcoming repair on the E90 to fix the trunk harness. I just did the one on my wife's Z4, wish I'd have seen this. I just don't understand why manufacturer's don't use this type of cable for this section of the trunk/hatch area. Every car I've had eventually has this issue.

[Greyfox]

Yep, had the same thing happen to one of my backup lights. Just took the harness apart and soldered in a new section of wire.

[gbalthrop]

Originally Posted by vilord

This is fine

Your posts on this subject have persuaded me NOT to use the tailgate in cold weather.

I had NOT looked at the wiring harness entry into the roof/chassis from the hatch before. When I first read these posts, I was trying to think of a design that would reduce horizontal flexion (hinge action) on the wiring as much as possible, and the first thing that came to mind was rotation of the wiring harness by having it enter the chassis at as great an angle as possible as opposed to perpendicular to the hinge line (so the wire sheath would twist as opposed to bend).

When I look at mine, it appears that was the concept BMW used in the design, but when I look at your "fine" photo, it is obvious that "as assembled" the design concept was NOT understood or followed.

It looks like (1) the total volume of wiring is too great for the size of the sheath and/or opening in the sheet metal, and (2) the wiring was "stuffed" into the opening any way it would fit, with NO regard to allowing enough space for the wiring harness to twist instead of bend. Worse yet, it appears that the wiring was jammed into the opening in such a way as to sharply flex it, even in its "at rest" position, so that it was pre-disposed to bend and ultimately break at those flex points.

So whether the flaw is deemed to be (1) in the design, or (2) in the assembly execution, the "fix" would appear to be to route the wiring in such a way that the harness twists or rotates longitudinally, with as little flexion horizontally as possible.

Just a thought, with NO practical experience with an actual FIX.

George

[vilord]

Hi George!

Not sure if it helps, but the cracked wires in the photo were in the middle of the rubber boot portion, not in the chassis. What you see is after I pulled the boot about 3 or 4 inches down the wires.

Jesse

[AM330i]

this happened on my 535 on the trunk harness. I cut about 6-8 inches out of the harness and replaced each wire by soldering in new wire. been about 3 years with no issues.