I recently bought car as transport to and from work my problem is: The aircon works but all the air goes through the defrost vents on the dash regardless of selector setting. From what i can tell i am not getting a vacuum from the surge tank on the intake manifold. I have checked all vacuum lines and none appear to be kinked / leaking. Any ideas where to go next would be appreciated.

Cheers.

 

Possibly the controller switch itself. Hard to troubleshoot on a forum.

 

Definitely the first thing I would check is the switch. Had this issue with an older vehicle I had but it wasn't a Hyundai.

 

Thanks guys, i have swapped the aircon control panel, including switch obviously and it has made no difference. have also change the actuator that is connected to the diverter that directs airflow from defrost vents to front vents and that also made no difference. I think the problem is somewhere in the intake manifold surge tank. I do not know how the vacuum is made in that tank though so i dont know where to look next.

 

I have isolated the fault to a very weak vacuum in the intake manifold surge tank. Does anyone know what may cause the vacuum to be so low? Am guessing maybe a gasket or something but any ideas would be appreciated.

Cheers