How I wish I could get warm!

[bowline5]

The heater in my 02 plate B6 has not worked for several months. Over that time I have drained, flushed refilled and bled the cooling system twice; the matrix is not blocked, hot water passes through it OK, and there are no leaks. I have replaced the air intake temperature sensor but all I have achieved is lukewarm air coming out of the defrost vents which is accompanied by a blast of cold air in the footwell. The next thing to check is the flap motors, where the connectors have five wires going into them. Anyone got a wiring diagram? Apparently there are two more temperature sensors in the cabin, but where? Can they be accessed and tested? If all else fails I guess I'll have to resort to eBay and take the risk of a second hand AC controller. Any advice or suggestions gratefully received.