Another HVAC question - Jeep Wrangler Forum
Jeep Wrangler Forum

Go Back   Jeep Wrangler Forum > TJ Jeep Wrangler Forum > TJ Tech Forum

Join Wrangler Forum Today


Reply
 
Thread Tools

Please support our sponsors and let them know you heard about them on WranglerForum.com
Old 06-23-2014, 04:55 PM
Thread Starter
  #1
Jeeper
 
Join Date: Feb 2012
Posts: 146
Another HVAC question

I've searched through several posts on here and could not find any that matched my exact symptoms. The switch that cycles the air flow between defrost, floor and face seems to be malfunctioning. Air conditioning blows cold but the air only comes out of the floor. When I first turn it on it comes out of the defrost but then switches to the floor (I am trying to get it to come out of the dash board vents/ face setting). Also after the air is blowing on the floor I can not get it to switch to the defrost setting. Any tips will be appreciated!

Tjrubicon17 is offline   Quote
Old 06-23-2014, 05:26 PM   #2
Jeeper
 
Letzride's Avatar
 
Join Date: Jun 2014
Location: Toronto, ON
Posts: 551
Oddly enough I have this exact problem...Ive wondered if it had to do with the switch being damaged. My switch wasn't working at all, I unscrewed it, pulled it out and found that the 3 wires going into the selector side of the switch (the one with floor/face/etc) was all burnt up. So I pulled the wires, cut them, put connectors on the end and plugged them back in.

HVAC switch worked great, except for defrost and strictly floor I think. But you can have it do both floor/defrost, so it is just two settings not working...I've wondered two things

a) is there a relay for the HVAC unit that is maybe toasted?
b) do you have burned damage on the back of your switches as well? My thoughts are I wonder if the switch itself has been damaged and is now malfunctioning.

__________________
1996 3.8L v6 Camaro - Fastest N/A v6 Fbody in Canada
2002 LS1 Camaro - soon to be fastest LS1 bolt ons only in Canada
1999 Jeep TJ - 4" lift on 33's

Jeep Build| LS1 Build | 3800 Build
Letzride is offline   Quote
Old 06-23-2014, 05:37 PM
Thread Starter
  #3
Jeeper
 
Join Date: Feb 2012
Posts: 146
I just tore mine apart. I have an 05. I remember there being 4 wires that go to that switch. Anyways, I had no burn damage or evidence of excessive heat. All the plastic and wires looked and smelled perfectly fine. I actually took the whole switch apart and there was nothing burnt up in there either. Everything had a nice coating of grease and all the copper looked very much intact. The only thing that seemed a little out of place was the vaccume line connection behind the glove box. For some reason there is a spot where a hose looks like it would go. But I don't think that's the problem since there is no hose insight to connect up to it.
Tjrubicon17 is offline   Quote
Sponsored Links
Advertisement
 
Old 06-23-2014, 08:08 PM   #4
Jeeper
 
Wattapunk's Avatar
 
Join Date: Mar 2012
Location: North TX
Posts: 3,086
It sounds more like a vacuum issue than switch. Check all vacuum hoses under the hood for cracks and disconnects(especially the one on the manifold by the TB). Then look under the dash under your right knee at the 3 vacuum actuators that controls vent selections. Check the function while you move the vent selector switch. They should move accordingly. Sometimes the arms get disconnected from the actuators or the actuators are just in need of replacement.
Wattapunk is offline   Quote
Old 06-23-2014, 08:28 PM   #5
Jeeper
 
Mom sold the Jeepster's Avatar
 
Join Date: Mar 2012
Location: Cincinnati
Posts: 284
New heater knob fixed it for me, $3. Old one wasn't gripping the post because it was cracked inside
Mom sold the Jeepster is offline   Quote
Old 06-24-2014, 06:42 AM
Thread Starter
  #6
Jeeper
 
Join Date: Feb 2012
Posts: 146
I will look again, but when I was in there last night i only saw 2 actuators. The one higher up (behind the steering wheel area) seemed to be working properly. I put the air on feet mode and then pulled the vaccume line to the upper actuator. The flap inside instantly flopped shut and the air stopped blowing on the feet setting. The lower actuator (behind the gear shift) did not have the same result I tried pulling the line when it was on defrost and then again on face. And there was no change. So I assume that the lower actuator is responsible for the face setting. Here is the question: how can I test if the actuator is bad or if there is a problem with the lines going to the actuator?
Tjrubicon17 is offline   Quote
Old 06-29-2014, 09:41 PM
Thread Starter
  #7
Jeeper
 
Join Date: Feb 2012
Posts: 146
Ok. So I finally tracked it down to a loose connection to the main vacuume line coming off the intake manifold. Didn't cost me a dime to fix it and it was very easy. Diagnosis was the hardest part.

Tjrubicon17 is offline   Quote
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off






All times are GMT -5. The time now is 11:40 PM.


Powered by vBulletin® Version 3.8.8
Copyright ©2000 - 2019, vBulletin Solutions, Inc.
Search Engine Optimization by vBSEO 3.6.1
User Alert System provided by Advanced User Tagging v3.1.0 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2019 DragonByte Technologies Ltd.

Jeep®, Wrangler, Liberty, Wagoneer, Cherokee, Gladiator, Mopar and Grand Cherokee are copyrighted and trademarked to FCA US LLC.
Wranglerforum.com is not in any way associated with FCA US LLC.