Hi, I have an 07 plate GTI which has dual zone climate control. Recently the system seems to go to sleep in that when I first drive the car everything is as it should be in all respects. (Temperature and air flow) However after a period of time I notice that the airflow has dropped right off. It is far more of a drop off than you would expect even though the temperature in the car has adjusted itself. It is possible to manually turn up the fan speed but even at max the through flow is well below what the dial setting should be delivering. If, on a long journey, I turn the system off for 10 to 15 minutes and then switch it back on then all is good until it decides to "go back to sleep". When working the air can be set either very cold or very hot and I believe that the system does not need re-gassing. My guess is either a sensor or something to do with the fan speed control. Anyone got any ideas please? Also information on where the sensors/fan are and how, if at all, it is possible to test them. Please. Thank you in advance Nick
Its possible the air con pressure sensor at the front of the engine bay is playing up, iirc they used to be a fairly common fault on earlier mk5s. If you have access to vagcom it would be worth doing a code read to see if it flags up any faults on the hvac circuit or you can look at the measured value blocks whilst operating the aircon to get a better idea of what's happening when it plays up. Failing that then get the system pressure tested by a competent ac specialist to see if it's making the correct pressure.
Thanks nealey, I'll get my son's code reader and have a look. For info the high pressure switch ( V1K0 959 126 D ) was replaced in July 2010 after the air con failed on the hottest day of the year!! Nick
