A/C blows through the Defroster - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Grand Cherokee & Commander Forums > ZJ Grand Cherokee Forum > A/C blows through the Defroster

Rockridge 4WD IS Taking Zone Offroad Suspension Lift Kits BLACK FRIDAY SPECIALS!! You asked, we deliver!Rough Country Lift Kits and Parts!

Reply
Unread 05-16-2012, 11:35 PM   #1
idahospudjeep
Registered User
1995 ZJ 
 
Join Date: Apr 2012
Location: Nampa, ID
Posts: 8
A/C blows through the Defroster

HELP! Its getting hot in Idaho and when my 95 Jeep Grand Cherokee Laredo 4.0 is at just an idol it will blow correctly out of the vents but when you start to drive it and foot on the gas it blows out of the defroster. Its cold air. (no matter what setting I'm at for the flow of air). Just would like to know if anyone else has had this problem and if anyone knows how to fix it or what is wrong. All the help the better....feel free to even e-mail me at shannon.egusquiza@yahoo.com

All Help Is Very WELCOME!

idahospudjeep is offline   Reply With Quote Quick reply to this message
Unread 05-16-2012, 11:59 PM   #2
Uniblurb
Web Wheeler
 
Uniblurb's Avatar
1996 ZJ 
 
Join Date: Jan 2012
Location: Central, Ohio
Posts: 3,834
Default for air circulation is out of the defroster when the main blend door isn't working correctly. Sounds like a bad actuator or vacuum leak. Look up right above the gas pedal under the dash and you will see the actuator with a piece of flat metal linkage going to the middle/underneath of the HVAC box to the main blend door. Make sure the vacuum hose isn't partially off or leaking.

Also in the engine compartment you will see a black vacuum line running across the firewall from the intake. There's a small black line which T's off which goes through the firewall which leads to your HVAC vent control switch. Also listen and look for vacuum lines here. This line also goes under the battery tray where the rubber hose can rot off causing not enough vacuum/leaks. You'll need to also listen to the dash for hissing vacuum leaks if you can't find any elsewhere. Good luck and let us know what you find.
Uniblurb is online now   Reply With Quote Quick reply to this message
Unread 05-17-2012, 12:26 AM   #3
idahospudjeep
Registered User
1995 ZJ 
 
Join Date: Apr 2012
Location: Nampa, ID
Posts: 8
We checked by the gas pedal and everything checks out there. In the engine compartment where the line goes under the battery we found that line to not be connected to anything and not rotten or any leaks at all. It just looks like it slipped off from some where and we don't have a clue where it goes. I will try to google some answers but if you know then that would be great also.

Thanks again.
your post was a big help.
idahospudjeep is offline   Reply With Quote Quick reply to this message
Unread 05-17-2012, 12:32 AM   #4
Oldfrog
Web Wheeler
1997 ZJ 
 
Join Date: Feb 2008
Location: Louisiana/Texas
Posts: 4,127
Mine does that occasionally when I accelerate. I let off the gas a little and it goes back to the vents. A Jeep tech once told me that he used to put a check valve in one of the vacuum lines to cure that issue. I've never fixed it, because it doesnt do it all the time.
__________________
Cajun Recipes and Fishing tips

Words of wisdom, Posted by Zeejay:
"..it's not air, it is the opposite of air... suckage so to speak."

Stalling? Work through Zeejay's list
Oldfrog is offline   Reply With Quote Quick reply to this message
Unread 05-17-2012, 12:54 AM   #5
Uniblurb
Web Wheeler
 
Uniblurb's Avatar
1996 ZJ 
 
Join Date: Jan 2012
Location: Central, Ohio
Posts: 3,834
Quote:
Originally Posted by idahospudjeep View Post
We checked by the gas pedal and everything checks out there. In the engine compartment where the line goes under the battery we found that line to not be connected to anything and not rotten or any leaks at all. It just looks like it slipped off from some where and we don't have a clue where it goes. I will try to google some answers but if you know then that would be great also.

Thanks again.
your post was a big help.
YW. So is the vacuum line you found under the battery box just open with no plug or anything in it? If so that might be your problem. It should have a short rubber line, remove the battery tray, there's a plastic nipple on the very bottom of the tray, and plug it in. That may fix it if line is open and causing little vacuum getting to your HVAC circulation switch.
Uniblurb is online now   Reply With Quote Quick reply to this message
Unread 05-17-2012, 01:13 AM   #6
jnicewan
Registered User
1995 ZJ 
 
Join Date: Dec 2010
Location: Norman, OK
Posts: 2,033
^ like he said, under the battery tray is a vacuum reservoir tank, its a small storage tank for vacuum pressure for when the engine is at heavy throttle (not producing vacuum). That vacuum line supplies the speed control and HVAC.
jnicewan is online now   Reply With Quote Quick reply to this message
Unread 05-17-2012, 02:02 AM   #7
idahospudjeep
Registered User
1995 ZJ 
 
Join Date: Apr 2012
Location: Nampa, ID
Posts: 8
i found what you where talking about and connected it so i will find out if it works tomorrow thank for the advice.
idahospudjeep is offline   Reply With Quote Quick reply to this message
Unread 05-17-2012, 03:47 PM   #8
Uniblurb
Web Wheeler
 
Uniblurb's Avatar
1996 ZJ 
 
Join Date: Jan 2012
Location: Central, Ohio
Posts: 3,834
YW, good luck, and hope it works.
Uniblurb is online now   Reply With Quote Quick reply to this message
Reply

Tags
1995 , 4.0 , a/c blower switch , defroster , switch

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.