Clicking noise front passenger window control unit '02 V70XC

[volvoswede]

Hi!

I own a 2002 V70 XC.

A fast clicking noise is coming from the window control unit in the front passenger door when the outside temperature is around or below freezing. The light in the buttons on the unit are also flickering when this noise is present. This all occurs even when the ignition is turned off and the battery seems to be discharged from this as well.
The clicking noise can be aggravated by opening and closing the other doors on the car.
Does this sound familiar to anyone?

I took apart the unit yesterday to see what's in there and got surprised how big the circuit board is. Does anyone know exactly what this unit controls?
I thought the driver side unit was the mother ship. This unit seems to do a lot of things because there are three chips in there, which seems like a lot to only control one window and a lock.