UK-POLOS.NET - THE VW Polo Forum

Yup fox,

Here we come.
I think my VW Polo is starting to drive me crazy.

On the well know issue of this model, the damaged Wiring Harness in Trunk Lid Grommet.

It started yesterday while I was driving back to my home
Message alerte "Check third brake light"

VCDS scann: Short to Ground b+

Smells very bad.

I removed the third brake light assy as it's a let module and tested the voltage output at the connector while pressing the brake pedals.
V=0V.

Funny thing, when I closed it (the trunk), at middle course, the light was working.
When fully closed, light goes off.

So for sure, I have a harness issue.

Two option: temporary repair or harness replacement and I will be free of issue for the next 12 years.

What do you think ?

depends on how often you open your trunk and if the wires are brittle.
mine were brittle, i replaced the whole harness in the end

amer6R wrote: Tue Feb 17, 2026 9:40 pm depends on how often you open your trunk and if the wires are brittle.
mine were brittle, i replaced the whole harness in the end

I use my trunk every day so put so "light" things inside (my meal mainly for the shift) so yeah, after so many years, it gives up.

Replacement seems quite easy. You just need to remove trunk trim and the side trim panel on the trunk compartment.

6C6971145A = AM/FM diversity.

It's always best to replace the entire wiring harness. The price is relatively affordable.

I would personally repair it, but my skills in repair, diagnostics, or wiring harness fabrication/creation are exceptional...

ciclo wrote: Wed Feb 18, 2026 2:19 am
6C6971145A = AM/FM diversity.

It's always best to replace the entire wiring harness. The price is relatively affordable.

I would personally repair it, but my skills in repair, diagnostics, or wiring harness fabrication/creation are exceptional...

I'm also quite bad concerning wire repair so...

Here the price (in France) is more around 130-140 euros...

I've repaired these rear hatch cables two times, ie on 2 cars, each time I repaired by adding in an extra length of wire(s) so that the repair area, or areas, are well away from where the cable flexes when opening the rear hatch - never attempt to create a repair exactly at the point where the cable(s) failed due to flexing.

My friend, who prefers to run older SAABs, did once, repair a broken wire that moves with the rear boot lid, this happened just while he was visiting us, all he needed me to give him was the brass/metal part from inside a "chocolate block" terminal block - that wire ended up being quite tight and he said that he would repair it properly "some time later" - that repair was still "good" when he scraped that car 3 years later - oh well, so much for needing to do things properly!

If you decide to swap the harness, be careful when pulling it out. Guide the connectors with your hand when you start pulling, because they can get stuck, and then it's a pain to get it to move.
Like this happened to me on the second occasion...

amer6R wrote: Thu Feb 19, 2026 5:14 pm If you decide to swap the harness, be careful when pulling it out. Guide the connectors with your hand when you start pulling, because they can get stuck, and then it's a pain to get it to move.
Like this happened to me on the second occasion...

In the C pillar ? Yeah, seems pretty tight inside. But I really carefull in general (maybe too much) ahah.

It's a good idea to use an electrician's guide wire so you can pull on both ends in either direction if you get stuck.
Example:

ciclo wrote: Thu Feb 19, 2026 6:24 pm It's a good idea to use an electrician's guide wire so you can pull on both ends in either direction if you get stuck.
Example:

Nice idea !

I think the most complicated part is the side of the trunk door (it seems very narrow).

Yes, the curve at the bottom (in the image) might be the trickiest part, be patient, go back and forth little by little. Easy for you!

ciclo wrote: Thu Feb 19, 2026 7:30 pm Yes, the curve at the bottom (in the image) might be the trickiest part, be patient, go back and forth little by little. Easy for you!

Yeah sure, patience is key.

But, I have a question, how are connected the rear windows heater (they is two black solid wire on each side) ?

Only the side lower trim of the trunk need to come out or also the C pillar ?

I have only one photo of this area, but it's hidded by the belt.

enlaces permanentes de imágenes



More images here: viewtopic.php?p=608321#p608321

ciclo wrote: Thu Feb 19, 2026 7:58 pm enlaces permanentes de imágenes



More images here: viewtopic.php?p=608321#p608321

Okey so a little bit of a mess...hmm I will have to way with temporary repair until the nice and warm days will be back.

No, it's easier than it looks in the picture. The apparent mess in this 'old image' is because my 6R is overloaded with non-original wiring harnesses.