Electric Window motor controller issue

Hi there, after spending numerous hours in the freezing cold with a multimeter I can say that there isn't a wiring issues on the drivers door of my 2005 VW polo, this part (see image) is attached to the window motor on the drivers side door. Im assuming it's responsible for the 'one touch' feature with the windows as they are able to open and close without you having to hold the switch. However through some testing I have figured that this might be why both windows are working intermittently. I came to this conclusion when I turned the ignition switch on and pressed the window switch down on both sides of the car and got nothing. I then proceeded to remove the larger plug from the top of this part and place it back in and then to my surprise the windows worked, and then they stopped, the issue I'm having is that the windows didn't stop working after I turned the ignition off and then back on again, it was almost as if it were timed. There is no corrosion on any of the contacts and non of the pins/clamps are bent out of place. is it worth spending £35 to replace this part in hopes it fixes the issue or have I wondered from the beaten track. please advise thanks very much.