climate control

[salty]

CAN ANY ONE HELP I HAVE A 1997 A6 1.9TDI AFTER ABOUT 30 MINS OF RUNNING THE CLIMATE CONTROL STOPS WORKING AND GOES ONTO FULL FAN BLOWING COLD. LEAVE THE CAR FOR A FEW HOURS AND IT ALL WORKS AGAIN PERFECTLY FOR 30 MINS THEN MY FEET FREEZE

[gazza57]

There are a number of sensors which provide the climate controller with the necessary information to determine whether the temp in the cabin is below the desired temperature hence it will heat, or above the desired temperature hence it will cool.
I suspect one of those sensors is malfunctioning, from the symptoms you described, it is probably a temperature related breakdown of the sensor, ie it works perfectly when cold from startup,but then malfunctions after it has warmed up.
As there are a number of sensors at different locations, the best way to check is to get the climate controller interrogated to determine if there are any fault codes present, if there are the fault code should tell you which sensor is at fault. I don't know if you can get this done independently or if you need to take it to Audi.
Hope this helps
Regards
Gazza57