AC Climate Control Unit/Blower

[vmoreno3049]

Hi, I have a 2012 A3 that is having issues with the AC. When I turn on the car an the ambient temp is hot outside, the blower does not engage and the AC Control Unit becomes unresponsive (the auto button stay on, changing the temp higher or lower will cause the display to turn off and only comes on when you move the temp dial to the original temp setting, speed can go up and down but no response from the blower).

After 15-20min, the blower will kick in and work as normal, as well as the control unit.

Any ideas as to where my trouble is would be appreciated. Checked codes and nothing showed up. I am leaning towards the control unit, but would like to be sure. Also, read on another thread that there are some special tools to uninstall the control unit. If someone has the link to purchase, please let me know.

Thanks in advance!

 

[vmoreno3049]

Update: checked the output pin on block B that powers the blower resistor and saw the voltage oscillate from 1v (blower on) down to 0.35v (blower shuts off). I ordered a replacement, 8P0820043BN XHA Climate Control Unit.

However, when I received it and installed it, all the buttons work, except the AC button. The AC button only lights up and turns on the AC compressor when I hold it down. As soon as I let it go, it shuts off. Faulty replacement? Do I need to do anything with the computer to sync with the new AC module?

 

[AudiRace]

Update: checked the output pin on block B that powers the blower resistor and saw the voltage oscillate from 1v (blower on) down to 0.35v (blower shuts off). I ordered a replacement, 8P0820043BN XHA Climate Control Unit.

However, when I received it and installed it, all the buttons work, except the AC button. The AC button only lights up and turns on the AC compressor when I hold it down. As soon as I let it go, it shuts off. Faulty replacement? Do I need to do anything with the computer to sync with the new AC module?

no just go to local garage and regas AC