A recurring problem on VW for multiple generations is broken wires in the door wiring harness connection. As the door opens and closes, the wires bend and over 100,000 miles or so, the insulation wears down and the wires short or the wires break. This can cause strange problems with opening, closing, or locking the door or windows. The driver's side harness is the most vulnerable since this is the door most often used.
The best solution is a new wiring harness. The correct part number goes
by the VIN number since different equipment levels/build dates required
different harnesses. The repalcement harness will be slightly longer. VW fixed it by lengthening the harness where it bends so this problem shouldn't be as common on the newer years. Below is a pic from clickman showing the difference (thank you clickman!)
If this is a Canadian car and model year 2006, there was a class action suit which got VW to reimburse for past repairs on this and extend the warranty on this part to 8.5 years/ 165,000 kilometers.
T20, T30 torx bits
Soldering equipment or new harness
For support on this topic, please post in this forum thread.
To check for a broken wiring harness or check the state of your wiring harness, open the door and have something hold it in case the wind blows it shut. There's a mechanism to hold it open but a strong gust of wind could still move it. Make sure the window is rolled up before you unplug the battery. Unplug the negative cable on the battery. See 1000q: battery removal if you need more details.
Grab the rubber tab at the top of the boot and firmly press it down to release a hook. Then lift the boot a little and pull it back to expose the plug. The plug has an orange lock lever - rotate it to unlock and push the plug back. From here you can inspect the wiring harness for cracks.
Below middle is some more detail on the hooks that hold the rubber
boot. Below right is some more detail on the door side of the boot.
You must remove the door skin to get the boot completely off.
Here's a better view after removal showing the broken insulation on the two
There isn't much clearance so if you want to
expose a lot of the wiring you have to remove the exterior door skin. See 1000q: door
skin removal for details.
It should look like this. Here you can see the areas of interference
where you should apply some tape to protect the door skin from scratches.
This will expose enough of the cracked wiring harness so that you can repair
it as necessary. The wire harness gets close to the window rail so it has
some thick padding wrapped around it there. If you need to replace the
harness, see below.
Although the mk5 and mk6 Jetta, Golf, JSW, GSW (sportwagen) all have 5 star side impact ratings, I hope that seeing how little "armor" is in the door should shatter the illusion of cars as tanks and encourage defensive driving practices.
If you wish to replace the door wiring harness, also remove the interior door panel. See 1000q: door card panel removal for details. The white box on the right is the door lock module and can also cause symptoms with locking/unlocking the doors. If the door doesn't seem to know that it was opened (from interior lights or alarm symptoms), and the wiring harness is fine, it's possible this is the problem. Please post in the myturbodiesel.com forum for more troubleshooting steps.
My wiring harness had the part number on a paper tab. The white tab is visible at the 1 o'clock position relative to the speaker. You can use this to find the correct replacement.
Unplug the door lock module, window motor, side view mirror plug, and other
plugs. The green clips hold the wiring harness in place. Clamp and
press the other side to push them back out through the door so you can reuse
If you need more information about how to repair the door panel wiring, ask in the myturbodiesel.com forums or search the site below: