had my climatronic refilled etc yesterday, problem is, guy that did it said it isnt starting air con fan under bonnet which means something is wrong with control unit to fan, connections are fine, its just something electrical, anyone know if air con control is available to buy not from vw? engineer put 12 volts to fan and compressor started working and cold air blowing through vents, take the 12 volts off and cold air stops. any ideas? crasher?