Heater Problem RR L322

The heater/aircon on my L322 works when it feels like it but never at the right time. When it works it works fine but then just stops. I replaced the resistor regulator and it worked for a little while then stopped again. It will comeback on when it feels like it. I have been told the motor is faulty but surely if that was the problem the rear motor would still work. The lights on the switch move as if they should be ok but the motor is silent.

Does anyone have any suggestions. I know you guys are more into traditional Land Rovers but I am running out of ideas and thought you would be the best ones to help me out here. Thanks for listening.