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JeepFreak12 01-20-2012 01:43 PM

heat problems
I have a 99 grand cherokee limited, with the dual climate control, it only blows out warm are on the drivers side. I have the heat temp turned all the way up on both driver and pass. side. Any ideas? Thanks guys

cheapjeep 01-20-2012 02:13 PM

Re: heat problems
First try unhooking your battery for 5 min and see if that helps.If not you may heve the dreaded blend door issue. Don't get too discouraged at the following link. Since then procedures have come about to fix this without dash removal. Do a search on "WJ blend door repair"

Overspin 01-20-2012 09:19 PM

Re: heat problems
Hey, 4.7beast, here's a copy of a thread I posted a couple of days ago with the title "anyone getting cold feet?" might save you changing blend doors.....

I had this problem with my '04 WJ with Automatic Zone Climate Control. There is lots of heat available, but only on the passenger side. Driver's side was getting only cold air. Pretty uncomfortable at -20C!

The blend doors for the heater and A/C could be broken, and has info on checking for that and replacing broken blend doors if necessary. But before you do all that....try this.

Calibrate the AZC door actuators as follows:
- Turn ingnition on
- Set AZC to automatic
- Turn ignition off
- Remove the IOD fuse from the Power Distribution Center (the manual shows you where this fuse is located) Wait several seconds, then reinstall the IOD fuse.
- Turn ingition on. Do not touch any of the AZC controls for at least one minute to allow the calibration function to run to completion.

There are additional details on for AZC self-diagnostics too, to check for blend door function, and at the very end of the site, a drawing to help locate the IOD fuse.

Give it a try. Costs nothing, takes five minutes, and if your problem is only the actuator function you can have full AZC back fast......and nice toasty warm air on those cold winter nights!

Overspin 01-20-2012 09:42 PM

Re: heat problems's a link that should help......

Lambar12 01-21-2012 07:12 PM

Re: heat problems
Overspin- Ihave the same problem in my 2004 gc, does your fix work for that model year?

Overspin 01-21-2012 09:16 PM

Re: heat problems
It does, Lambar 12, my GC is an '04. I ran the recalibration in November, and no problems since. Follow the link I sent above, and you will be able to find the IOD fuse.

You might also want to do the diagnostic check, set out in jeep heater site. That will tell you if the doors are not working properly, but not if they are broken. To check for broken doors, follow their instruction to remove the glove box door, the heater door motor, and then the door function.

Meanwhile, if you just do the recalibration first. After a few minutes you should know if that was the only problem.

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