A/C lines 
A/C Question
Thread Starter
Burning Brakes
Joined: May 2003
Posts: 990
Likes: 0
From: Germantown TN
A/C Question
I know I'm going to sound stupid but here it goes. For the A/C there are 2 buttons. One drawing air from inside the car while the other seems to circulate air from the outside and it makes the A/C blow harder. My A/C doesn't blow harder anymore once either button is pressed.
Has anyone ever had this problem? What could be the culprit? Also what should I check first?
Has anyone ever had this problem? What could be the culprit? Also what should I check first?
Drifting
Joined: May 2000
Posts: 1,917
Likes: 3
From: Southern NH
I know I'm going to sound stupid but here it goes. For the A/C there are 2 buttons. One drawing air from inside the car while the other seems to circulate air from the outside and it makes the A/C blow harder. My A/C doesn't blow harder anymore once either button is pressed.
Has anyone ever had this problem? What could be the culprit? Also what should I check first?
Has anyone ever had this problem? What could be the culprit? Also what should I check first?
Are you also noticing that there's not change in airflow when you select different vent settings, i.e. Dash vs. Floor vs. Windshield?
If the problem is affecting the airflow mode AND the recirc setting then the issue is likely your vacuum line coming from the engine compartment into the dash that controls the vacuum actuators that move the doors for airflow/recirc. The vacuum line passes through the firewall below the battery and it's not uncommon for the line to spring a leak resulting in no vacuum, hence no airflow changes.
If the problem is only the recirc setting, then that vacuum actuator may have gone bad and is no longer able to move the recirc door, or the door is stuck.
Hope this helps.
Thread Starter
Burning Brakes
Joined: May 2003
Posts: 990
Likes: 0
From: Germantown TN
You didn't mention whether you have the manual HVAC or electronic Dual Zone HVAC unit, but my response shouldn't matter.
Are you also noticing that there's not change in airflow when you select different vent settings, i.e. Dash vs. Floor vs. Windshield?
If the problem is affecting the airflow mode AND the recirc setting then the issue is likely your vacuum line coming from the engine compartment into the dash that controls the vacuum actuators that move the doors for airflow/recirc. The vacuum line passes through the firewall below the battery and it's not uncommon for the line to spring a leak resulting in no vacuum, hence no airflow changes.
If the problem is only the recirc setting, then that vacuum actuator may have gone bad and is no longer able to move the recirc door, or the door is stuck.
Hope this helps.
Are you also noticing that there's not change in airflow when you select different vent settings, i.e. Dash vs. Floor vs. Windshield?
If the problem is affecting the airflow mode AND the recirc setting then the issue is likely your vacuum line coming from the engine compartment into the dash that controls the vacuum actuators that move the doors for airflow/recirc. The vacuum line passes through the firewall below the battery and it's not uncommon for the line to spring a leak resulting in no vacuum, hence no airflow changes.
If the problem is only the recirc setting, then that vacuum actuator may have gone bad and is no longer able to move the recirc door, or the door is stuck.
Hope this helps.
I do have the electronic dual zone HVAC. I tried it today and none of the modes will change either along with the recirc. The air comes out of the windshield vents, floor, and face level vents.
Thread Starter
Burning Brakes
Joined: May 2003
Posts: 990
Likes: 0
From: Germantown TN
Former Vendor
Joined: Feb 2004
Posts: 10,876
Likes: 8
From: Las Vegas NV
St. Jude Donor '06 & '12
The lines run into a vacuum canister on the outer side of the passenger fraim rail, right behind the PCM. One of my vacuum lines broke and caused the same problem. It was a 9.00 fix from GM.
Melting Slicks
Joined: Dec 2005
Posts: 2,654
Likes: 3
From: Florida
I don't mean to hijack this thread but I have a similar problem. After installing a new battery my heat does not seem to work although the defroster does blow hot air. Pushing the Auto button does nothing at all. I can manually move the fan speed up and down several times and it will eventually start to blow. The a/c blows cold air after that. I do have a couple of codes concering one actuator. Does anyone have some pics of the lines running under the battery and where they go?
Thanks in advance.
Thanks in advance.
Melting Slicks
Joined: Jul 2004
Posts: 2,567
Likes: 1
From: Edmond, OK...One of the first rules of online forums: If you don't like what is said but can't refute it, attack the poster.
I had the same thing happen in another GM car I have. The battery leaked and ate a hole in some of the ac vacuum lines under the battery. Fixed them and it all worked good.
jeff
jeff
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