Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here! ZJ (93-98), WJ (99-04), WK (05+)
All ZJ/WJ/WK specific tech questions asked here!

99 WJ only blowing air, not getting hot or cold

Old 10-29-2015, 08:22 PM
  #1  
Newbie
Thread Starter
 
Join Date: Sep 2009
Posts: 23
Model: Cherokee
Default 99 WJ only blowing air, not getting hot or cold

Anyone have any ideas why this would happen? I tried swapping the control unit with no luck. It did have the same issue every cherokee had with the resister/module overheating and melting the prongs etc. I fixed that. But now it's just "air". Won't get hot. Won't get cold. Fuses look ok. Everything seems plugged in and ok. Has anyone had this same issue? Or know a fix?
antp1987 is offline  
Old 10-30-2015, 07:24 AM
  #2  
Member
 
Join Date: Dec 2010
Location: East Sussex, UK
Posts: 109
Year: 2000
Model: Grand Cherokee
Engine: 4.0 Petrol
Default

Most likely the blend doors...
You can get a repair kit - the fix involves carefully cutting a hole in the side of the heater box to replace the broken / faulty parts.
Not too difficult to do - had to do mine a while back.
Repair kit is not too expensive.
Cherokee_Mike is offline  
Old 10-30-2015, 10:25 AM
  #3  
Senior Member
 
Join Date: Sep 2013
Location: Santa Cruz Ca.
Posts: 509
Year: 2000 WJ
Model: Grand Cherokee
Engine: 4.7
Default

You can check the blend door. Take out the glove box. You'll see the heater plenum behind it. You can see the pivot point for the blend door. Its like a door hinge. Twist it, like up and down. If you can feel the door and hear it moving up and down , it's okay. If it feels stuck , like you can't even move the end of the hinge, its jammed up. Or there is play in it the hinge is broken. You can go to the Heater Treater web site and follow the diagnostics. There is another site that escapes me right now, Doorman also sells a repair kit on AMAZON. Lots of options for repair.
blueseasons is offline  
Old 10-30-2015, 10:33 PM
  #4  
CF Veteran
 
dave1123's Avatar
 
Join Date: Nov 2010
Location: Manlius, east of Syracuse, NY
Posts: 11,267
Year: 2000
Model: Grand Cherokee (WJ)
Engine: 4.0L
Default

You forgot to mention there is a stepper motor mounted over the end of the shaft. The shaft is plastic and breaks easily. When you remove the motor, it's obvious if the shaft is broken. Dual zone heaters have 2 doors and the one in the rear requires removal of the dash.
dave1123 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Batman33165
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
6
11-04-2015 11:37 AM
Peter Saran
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
23
10-30-2015 10:22 PM
Redsox88
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
4
10-27-2015 09:15 PM
MtnGoat
Stock XJ Cherokee Tech. All XJ Non-modified/stock questions go here
3
10-26-2015 07:27 PM
ghostriderI
Stock Grand Cherokee Tech. All ZJ/WJ/WK Non-modified/stock questions go here!
2
10-25-2015 05:32 PM

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 

Thread Tools
Search this Thread
Quick Reply: 99 WJ only blowing air, not getting hot or cold


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.
 
  • Ask a Question
    Get answers from community experts
Question Title:
Description: