Extremely strange electric window behaviour

[vicciu]

Hi, I've got a mk3 GTI and the passenger window is behaving very strange. At first it would work most of the time with some exceptions. Now, the issue is getting worse and worse to the point where i have to pray to the windows gods to help me close it so that I can leave the car
After some troubleshooting it looks like the window starts working again if the car is left for a few minutes without the key, however as soon as I turn on the engine it doesn't work again. I checked the wires that are going to the door and they are good. I get 12V at the window swich and the swich seems to work correctly. Does anyone know any possible reason to this behavior?

[gasketface]

Regulator is a common problem.If you dissconnect glass from regulator does window slide up and down easily ?.Cable may be frayed and binding is another possibility.

[CameraJack]

Pull back the rubber concertina between the door and door frame.  You'll almost certainly have frayed or broken wires inside there.  I soldered and heat shrunk in replacement sections to my driver's door loom and boot loom, and my passenger door loom needs doing soon as the window won't go down when the door is open.  Sigh. 

[vicciu]

Had little time in the last days to work on the car. Today I had another look at it and all the cables are ok. It looks like gasketface was right, it is a regulator issue. I can trace the 12V signals up to the regulator connector and the motor also works perfectly. The only item that wasn't tested is the electronics board on the regulator and mosty probably it's faulty.