hey guys, im new to the world of cherokee's and unfortunately the one i have purchased has a faulty a/c and also vents. The a/c compressor pulley is noisey, i will replace it this week.

But another problem is the vents. Air only comes out of the windcreen defrost vents. When i first turn the fan on, it comes out of all the vents for 1 or 2 seconds - then the only vents that work are defrost.

If someone could point me in the right direction of where to find the fault that would be great, as most days are 40 degrees or more here in perth at the moment!

Ryan

 

Most common reason is a vacuum leak. Starting from the vacuum ball located on the passenger side under the front bumper. Check it for cracks or loose hose connections. Also fallow the vacuum hoses all the way to the fire wall making sure that none are crack or disconnected along the way. If they all are fine then you want to check the blend door under the dash to make sure that everything is operating correctly.
BTW, Welcome to the forum.

 

Generally a loss of vacuum control causes the HVAC door system to revert to the Defrost position. Refer to the following images and do a visual examination of the vacuum tubing and rubber couplings for being cracked, broken or disconnected.



To check the connection at the vacuum reservoir, climb under the right front bumper end cap and pull back the right inner fender liner and look up at the reservoir vacuum tube connection.



Occasionally the vacuum tube from the cruise control servo to the reservoir gets cracked or broken behind the battery. You may have to remove the battery to get a good look at it.



The vacuum source for the cruise control and the HVAC system originates at the intake manifold. Verify a good connection here.



The vacuum source to the HVAC system goes through a small check valve then through a 3 MM tube into the firewall, then to the HVAC Mode Selector. This 3 MM tube has been found broken or chafed by others so check it closely.



If you find no broken or chafed vacuum tubes you may have to do a vacuum check of the system using a vacuum hand pump. Later for this; for now inspect the vacuum system in the engine bay.

 

My fellow Aussie means Celcius here

THat would be the driver side for us RHD's

And welcome to this forum, and the picture database of CCKen

 

thanks for all your help guys - i found a cracked vacuum line and now it works great