I have a 2001 Jeep Grand Cherokee Limited V8 with Dual Automatic Climate Control. It's got a 155,000 miles on it and up until the last year it has worked flawlessly. Lately I have been having random problems here and there but that's to be expected.
I had been having problems with my blower motor wiring harness. The blower would fail intermittently and I found that jiggling the wiring would temporarily fix it. I took the harness off and found that it was melted as pictured at wjjeeps
. I ordered a new harness from the dealer but haven't replaced it yet.
Last week we had about 7 days of sub zero degree weather. One evening I noticed that while I had hot air comeing nicely out of the vents I could feel a draft that seemed to be coming from the passenger side floor. The next morning I had the same "no blower" problem. I jiggled the wires and the blower came on, however it was only blowing cold air out of the center dash vents. I could feel heat leaking out the side dash vents but freezing cold air blasting out the center vents. No matter which way I turned the vent control knob (floor, mix, vents, defrost...) it wouldn't change. Also, the Recirculation button did nothing. I ran the ATC/AZT self-diagnostics and it gave me back the following codes: 18, 20, 22, 56. From another google search I found that those mean:
18 - Mode door travel range too large
20 - AI (Recirc) door travel too large
22 - Left temperature door travel too large
56 - Right temperature door travel too large
From various threads on this forum I decided that I was having a Blend Door problem and Recirc door problem. I confirmed this with a friend that works at a Jeep dealership who checked with his service manager. I decided to do the "through the glove box fix"
for the Blend doors and to wire the Recirc door to only blow outside air (in 10 years I've never used the recirculation). I ordered some parts and they arrived this morning.
When I got out there to do the work everything was working properly again! Everything worked except the Recirc button didn't seem to do anything, the light would come on then go off again, however, the door and motor seemed to be operating well enough. Looking under the dash through the glove box, I noted that when I turned the heat off it would shift to the back, then when I turned the heat on it would shift forward fully, and like I said I was getting heat out of any vent I wanted it out of.
While I was down under the dash I figured that I'd fix the blower resistor harness but found that I couldn't remove it. It must have melted so much that it had become fused into the resistor housing. I had to unscrew the resistor to see what was going on and no matter what I tried I could not remove it.
This has left me with a few questions on how I should proceed:
: Why would the blend doors and recirc door be working again? It's about 32 degrees today so I'm wondering if maybe there was some moisture in the system and the blend door and/or recirc door froze shut?
I didn't want to cut through the glove box wall if it was working for fear of making it worse but maybe I should to further diagnose the problem.
What should I do about the wiring harness? I was thinking about cutting the whole resistor out and bringing it inside where it was warm and fixing like in this post
Am I missing something? Did I diagnose these problems wrong? Any thoughts would greatly be appreciated.
I am generally pretty resourceful. I'm good at taking things apart and fixing things even when I have no knowledge about them (however I break a lot of stuff too). I have three major resource constraints that may make this fix difficult: 1. very little money 2. no garage (so I have to do everything outside in the cold) 3. little patience (particularly when I'm cold).