AC compressor not engaging. Only blows hot air. - 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 > WJ Grand Cherokee Forum > AC compressor not engaging. Only blows hot air.

Introducing MONSTALINER™ UV Permanent DIY Roll On Bed LineFree Shipping on Soft ShacklesNew! JK/U skid plate system.

Reply
Unread 04-23-2015, 06:13 PM   #1
johnnyham89
Registered User
2002 WJ 
 
Join Date: Aug 2013
Posts: 30
AC compressor not engaging. Only blows hot air.

So of course when summer starts rolling around here in Houston my AC decides to go out. It appears that the compressor is not kicking on at all. I checked all fuses and relays which are all good. All I am getting is hot air. Any common issues with these models that would cause this? I keep on reading about the blend door issues but this can't be related. Can it?

johnnyham89 is offline   Reply With Quote Quick reply to this message
Unread 04-23-2015, 06:44 PM   #2
mr312712
MOPAR FOR LIFE
 
mr312712's Avatar
2004 WJ 
 
Join Date: Jul 2014
Location: , Michigan
Posts: 1,165
Make sure the clutch Is plugged In or It may need replacing.
__________________
I've Hit The Speed Limiter At 118 MPH
Don't Call An Engine A Motor
Quadra-Drive 247 Transfer Case
04 WJ Overland 4.7 H.O. Inferno Red
mr312712 is offline   Reply With Quote Quick reply to this message
Unread 04-23-2015, 07:01 PM   #3
befirst
Registered User
2000 WJ 
 
Join Date: Jul 2014
Location: hilliard, florida
Posts: 80
If you are not simply low on refrigerant, this may help.

I had a liberty that developed a similar problem. After years of use the clutches wore down and made the gap between the clutch and magnetic clutch plate too large, where the magnets would not be strong enough to engage. I had to remove the shims and tighten the gap. A simple way to check is start the jeep, turn on the a/c and then strike/ stab the front of the clutch assembly with a piece of broom handle or something similiar, I reccomend wood, not steel, DO NOT use your hand as this may cause the clutch to engage and you don't want your hand on it if it does. If the clutch engages when you strike it then you have excessive clutch wear and can possibly remove the shims to fix your problem. No gaurantee that this is your issue but it is worth checking.
befirst is offline   Reply With Quote Quick reply to this message
Unread 04-23-2015, 07:05 PM   #4
Acc0919mc
Registered User
2000 WJ 
 
Join Date: Jan 2013
Location: East Palestine, Ohio
Posts: 681
There is a sensor on the system, if the refrigerant is low it will not engage the compressor. This would mean there is a leak somewhere in the system. You can jump a connector and make the compressor come on but im not sure how to do it
__________________
150K Miles of Smiles, Swearing, and Bloody knuckles
Acc0919mc is offline   Reply With Quote Quick reply to this message
Unread 04-23-2015, 09:08 PM   #5
lincolnshibuya
Registered User
2000 WJ 
 
Join Date: Dec 2014
Location: Kansas City, Missouri
Posts: 141
use an ac manifold gauge to check the pressures, if it's low the compressor will not engage at all. Normally shorting the low pressure switch near the battery (accumulator/drier) will turn on the compressor. also make sure the A/C switch is on on the console.
__________________
http://www.facebook.com/diyjeepwj
lincolnshibuya is offline   Reply With Quote Quick reply to this message
Unread 04-23-2015, 10:33 PM   #6
HVACNY
Web Wheeler
 
HVACNY's Avatar
2013 WK 
 
Join Date: Feb 2011
Location: East Meadow, NY
Posts: 1,269
Just hook up some guages from autozone or the like..See if you have refrigerant in the system and proceed from there..

If you wouldnt run your jeep with no oil in it,dont run your compressor with no refrigerant in it:ie jumping out the low pressure safety switch..nothing good is gonna happen
__________________
2000 Jeep Grand Cherokee 4.7 V8

2013 Jeep Grand Cherokee Overland 5.7 Hemi
HVACNY is offline   Reply With Quote Quick reply to this message
Unread 04-24-2015, 07:15 AM   #7
Acc0919mc
Registered User
2000 WJ 
 
Join Date: Jan 2013
Location: East Palestine, Ohio
Posts: 681
Quote:
Originally Posted by HVACNY View Post
Just hook up some guages from autozone or the like..See if you have refrigerant in the system and proceed from there..

If you wouldnt run your jeep with no oil in it,dont run your compressor with no refrigerant in it:ie jumping out the low pressure safety switch..nothing good is gonna happen
Yeah for sure, i just mean for a second to see if the compressor is good
__________________
150K Miles of Smiles, Swearing, and Bloody knuckles
Acc0919mc is offline   Reply With Quote Quick reply to this message
Unread 04-25-2015, 12:02 PM   #8
johnnyham89
Registered User
2002 WJ 
 
Join Date: Aug 2013
Posts: 30
I'm going to rent some ac pressure gauges from Autozone just to make sure that my lines still have some sort of pressure in them. Any tips on how to use these on a WJ? Or what pressure the lines should be reporting?
johnnyham89 is offline   Reply With Quote Quick reply to this message
Unread 04-25-2015, 12:18 PM   #9
mr312712
MOPAR FOR LIFE
 
mr312712's Avatar
2004 WJ 
 
Join Date: Jul 2014
Location: , Michigan
Posts: 1,165
Quote:
Originally Posted by johnnyham89 View Post
I'm going to rent some ac pressure gauges from Autozone just to make sure that my lines still have some sort of pressure in them. Any tips on how to use these on a WJ? Or what pressure the lines should be reporting?
My advice would be If u don't know how to do It dont mess with It. A/C Freon Is nothing to play with.
__________________
I've Hit The Speed Limiter At 118 MPH
Don't Call An Engine A Motor
Quadra-Drive 247 Transfer Case
04 WJ Overland 4.7 H.O. Inferno Red
mr312712 is offline   Reply With Quote Quick reply to this message
Unread 04-25-2015, 12:36 PM   #10
car5car
Registered User
2000 WJ 
 
Join Date: Apr 2007
Location: Florida
Posts: 571
Quote:
Originally Posted by befirst View Post
If you are not simply low on refrigerant, this may help.

I had a liberty that developed a similar problem. After years of use the clutches wore down and made the gap between the clutch and magnetic clutch plate too large, where the magnets would not be strong enough to engage. I had to remove the shims and tighten the gap. A simple way to check is start the jeep, turn on the a/c and then strike/ stab the front of the clutch assembly with a piece of broom handle or something similiar, I reccomend wood, not steel, DO NOT use your hand as this may cause the clutch to engage and you don't want your hand on it if it does. If the clutch engages when you strike it then you have excessive clutch wear and can possibly remove the shims to fix your problem. No gaurantee that this is your issue but it is worth checking.
There are specs for clutch gap, check it with feeler gauge, it takes 2 min.
__________________
00 WJ 4.0 2wd Laredo
car5car is offline   Reply With Quote Quick reply to this message
Unread 04-25-2015, 12:57 PM   #11
86cj74.2L
Registered User
2004 WJ 
 
Join Date: Jul 2006
Location: Stouchsburg, PA
Posts: 7,758
Quote:
Originally Posted by johnnyham89
I'm going to rent some ac pressure gauges from Autozone just to make sure that my lines still have some sort of pressure in them. Any tips on how to use these on a WJ? Or what pressure the lines should be reporting?
It's not as simple as just putting gauges on and going "yep that's it". The static pressure (pressure of system without compressor running) will only tell you if the system is way low on charge. It won't tell you there is 24oz of it in the system.

But, saying that if the clutch won't cycle at all the system is below the low setting of somewhere in the mid to upper 20's psi wise. And to me it's so low that at the minimum I'd replace both schrader valves and pump it down with a vacuum pump and see how long it holds a vacuum.
86cj74.2L is offline   Reply With Quote Quick reply to this message
Unread 04-25-2015, 11:28 PM   #12
MURDEREDWJ
Registered User
2001 WJ 
 
Join Date: Jun 2011
Location: Tulsa, OK
Posts: 45
Had this same problem. Recharging didn't help me. Turned out to be a very fine slit in one of the ac hoses that blew out all the charge over time and therefore wouldn't engage the clutch. Something to look at.
__________________
**MURDER IT**
MURDEREDWJ is offline   Reply With Quote Quick reply to this message
Unread 04-26-2015, 01:45 AM   #13
Ah673000
Registered User
2002 WJ 
 
Join Date: May 2013
Location: Philadelphia, Pa
Posts: 588
More then likely ( based on my experience with my '02) you are low on coolant .

It will cost you about $150 to have your system pressure tested - troubleshooter at a good local Indy .

I had a slow leak .... Repaired it with a product called Super Seal ($30) and have had no further leaks since 2012.
Ah673000 is offline   Reply With Quote Quick reply to this message
Unread 04-27-2015, 04:23 PM   #14
multmigs
Registered User
2003 WJ 
 
Join Date: Feb 2009
Location: browntown
Posts: 1,143
Quote:
Originally Posted by Ah673000 View Post
More then likely ( based on my experience with my '02) you are low on coolant .

It will cost you about $150 to have your system pressure tested - troubleshooter at a good local Indy .

I had a slow leak .... Repaired it with a product called Super Seal ($30) and have had no further leaks since 2012.
Its not coolant in the AC its R134a REFRIDGERANT... definitely need to have the systems pressure checked on both high and low side ports... And those super seal products are not the best as they are adding stuff inside the system to seal a hole etc from the inside out, its the equivalent of using the cans of tire seal goo that you inject from the tire valve. Its not a legit repair and then you have this gunk floating around inside which can mess up something else that is working later on. Both the AC clutch being worn out and the low amount of R134a are things you can repair yourself at home. You can also handle changing out the valve stems on the ports by using tools that are available on amazon that allow you to change without taking pressure out of the system.
multmigs is offline   Reply With Quote Quick reply to this message
Unread 04-27-2015, 04:54 PM   #15
dalton91
Registered User
2001 WJ 
 
Join Date: Mar 2014
Location: , Colorado
Posts: 36
Harbor freight... yes I said it.... has vacuum pumps for $20 and they do work. I am certified in A/C and do use the real machines but for at home and cheap, these do work if you have an air compressor. And jumping the low pressure cutoff switch is ok for checking and charging a low system. Just don't forget to plug it back in properly. Just low -- Google how to do it and give it a shot. However, if it is empty, it is worth taking to a shop and having them find the leak, repair it and replace needed components as you may spend more in the long run.

http://www.harborfreight.com/air-vac...ors-96677.html
dalton91 is offline   Reply With Quote Quick reply to this message
Reply

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






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.