2008Passat wipers not working

[Paul757]

This on behalf of my neighbour.
His wipers stopped working yesterday on his 58 plate Passat saloon. We checked both dude boxes (1 under bunnot, & 1 inside drivers door , pop of panel at right hand side of steering column.) Fuses are not blown. A suggested taking of the wiper stalk of the steering column & testing for power to the switch ....? To eliminate if the switch is faulty.
Any advice?
Am now thinking possibly the wiper motor could be potential problem, - no power reaching it, possibly?
Any suggestions are most welcome !

[Crasher]

The wiper motor is digitally commanded by a LIN BUS signal from the Body Control Module, this signal is initiated by the steering column switch sending a stepped varying resistance signal to the Steering Column Controller which is a different value for each position, this is then sent to the BCM as as digital CAN BUS signal via the CAN BUS controller. The motor has live and earth power so a conventional fuse and decent thick wires but the LIN BUS signal is sent from the BCM by a ridiculously thin (0.35mm² CSA) cable which is known for failing. The first step is to continuity check the wire from the BCM to the motor (I have the pin and connector information at work) and if this good and the power supply present then the motor MAY be faulty BUT a common problem is failure of the BCM itself. Before replacing any components it makes sense to have the car scanned in the BCM and SCC and if nothing is shown, check the Measuring Block values in both controllers to see if the SCC is seeing the wiper switch values and the BCM is receiving the CAN BUS signals from the BCM. Whilst communicating with the BCM, it is possible to use an Output Tests function to operate almost all the components it controls including the wipers so this working or not working helps narrow down the source of the problem.