LOST JEEPS :: View topic - Heating = An Exercise in Frustration

Not to sound incredibly arrogant here but the vents weren't blocked by chance were they? I mean the outside vents which suck the air in.

Have you checked the internal venting for possible fillups?

The dealership has been all over the rig several times... most recently only a few weeks ago... And they said nothing was wrong... Of course this is an intermittent issue so naturally there was nothing wrong when I brought it in.... :shock:

If it was constantly not working then I could definitely see that as a cause...

did you or they check to see if the blower motor restrictor is going bad? It is an issue on a lot of our rigs. I replaced mine this summer, its pretty typical for them to cause havoc.

it seems that you have the typical symptoms. blower will work fine and say settings 1 and 2, but not work on3 or 4. When the restrictor goes completely, no settings will work.

It's not a restrictor - it's a resistor - and if it's bad, then blower setting 4 works (straight 12 volts) but the other setting don't - because the resisor plugs in to lower the blower fan speed.

Author:	shadow [ Tue Jan 22, 2008 11:54 am ]
Post subject:	Heating = An Exercise in Frustration
So I have been dealing with an intermittent issue for a while now (read over a year!)... I have brought the issue up at two different dealerships but of course the problem never occurred when I brought the jeep in.... Therefore the supposed barrage of tests never identified a problem. That was until a couple of weeks ago when I picked my wife up from work... Basically what happens is the venting seems to lose its brains! The blower is working (should since one dealership assumed that was the issue and replaced it and then there was the recall not long ago which replaced it again!) and I can hear the air moving and the heat works because what little air escapes the vents is hot BUT that is the issue... When set on 4 there is the equivalent amount of air as if it was set on 1.... It sounds like it is on four as far as the noise in the dash is concerned! When it was malfunctioning the tech even said it was likely a vacuum hose issue but of course a few days later when I brought it in for service they couldn't replicate the issue and only ended up replacing the instrument assembly for setting the fan speed, temp, etc... And this was AFTER I actually brought it in with the problem happening!!!!! I am almost at the end of what little rope I have left... Hopefully there are others that have experienced similar issues or that can lend some expertise...

Author:	Uffe [ Tue Jan 22, 2008 12:19 pm ]
Post subject:
Not to sound incredibly arrogant here but the vents weren't blocked by chance were they? I mean the outside vents which suck the air in. Have you checked the internal venting for possible fillups?

Author:	Jeep4me99 [ Tue Jan 22, 2008 12:20 pm ]
Post subject:
did you or they check to see if the blower motor restrictor is going bad? It is an issue on a lot of our rigs. I replaced mine this summer, its pretty typical for them to cause havoc. it seems that you have the typical symptoms. blower will work fine and say settings 1 and 2, but not work on3 or 4. When the restrictor goes completely, no settings will work. The restrictor is a little credit card shaped unit which is located behind the glove compatment. It is held in place with 2 screws. It is very simple to replace and the piece itself is pretty cheap. may be worth trying if the issue is really driving you crazy. here is a thread on it from another forum, and explains how to replace it http://www.jeepkj.com/forum/showthread.php?t=26012

Author:	shadow [ Tue Jan 22, 2008 12:47 pm ]
Post subject:
The dealership has been all over the rig several times... most recently only a few weeks ago... And they said nothing was wrong... Of course this is an intermittent issue so naturally there was nothing wrong when I brought it in.... If it was constantly not working then I could definitely see that as a cause... Uffe wrote: Not to sound incredibly arrogant here but the vents weren't blocked by chance were they? I mean the outside vents which suck the air in. Have you checked the internal venting for possible fillups?

Author:	Jeep4me99 [ Tue Jan 22, 2008 12:50 pm ]
Post subject:
shadow wrote: The dealership has been all over the rig several times... most recently only a few weeks ago... And they said nothing was wrong... Of course this is an intermittent issue so naturally there was nothing wrong when I brought it in.... If it was constantly not working then I could definitely see that as a cause... it was intermittent for me at first too...just a thought though......good luck!! seems like a tricky one

LOST JEEPS http://www.lostjeeps.com/forum/phpBB3/

Heating = An Exercise in Frustration http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?f=1&t=28803	Page 1 of 1

Author:	shadow [ Tue Jan 22, 2008 12:51 pm ]
Post subject:
Jeep4me99 wrote: did you or they check to see if the blower motor restrictor is going bad? It is an issue on a lot of our rigs. I replaced mine this summer, its pretty typical for them to cause havoc. it seems that you have the typical symptoms. blower will work fine and say settings 1 and 2, but not work on3 or 4. When the restrictor goes completely, no settings will work. Thanks for the suggestion... I don't have the time to tear it down myself but I will most certainly ask the tech @ my dealership to look into it! This definitely sounds promising...

Author:	ATXKJ [ Tue Jan 22, 2008 1:14 pm ]
Post subject:
It's not a restrictor - it's a resistor - and if it's bad, then blower setting 4 works (straight 12 volts) but the other setting don't - because the resisor plugs in to lower the blower fan speed. That doesn't sound like the problem. The rest of the heater consists of the hoses that are open/closed with vacuum switches - i.e. you have a vacuum line that moves a plate that closes or opens a hose - that vents the air flow from feet - to dash to windshield - it sounds like one of the vacuum lines is pinched or leaking - not allowing a vent to open or close. Not sure of a good way to check. On my Camaro - I pulled out lower dash board pieces and traced them - not sure I want to do that with the Liberty. (sounds like the dealer doesn't want to either) Another possibility could be leaves or something being pulled into the outside vent and clogging lines - that's real common on vehicles parked under trees.

Author:	sleeve84028 [ Tue Jan 22, 2008 1:42 pm ]
Post subject:
The main blend door is vacuum controled and this has to be the problem. As ATXJK suggested: trace the lines from the HVAC control head to the actual HVAC unit and look for pinched or broken lines. The problem will be very hard to spot but this is certainly a vacuum issue.

Author:	Jeep4me99 [ Tue Jan 22, 2008 2:01 pm ]
Post subject:
ATXKJ wrote: It's not a restrictor - it's a resistor - and if it's bad, then blower setting 4 works (straight 12 volts) but the other setting don't - because the resisor plugs in to lower the blower fan speed. tomato, tomAto....restrictor, resistor. they actually are different though. but mine didn't work on 3 or 4 at first, then 2 went out, then finally nothing worked. not sure why, don't really care as long as its fixed.

Author:	valvestem [ Fri Jan 25, 2008 10:12 am ]
Post subject:
If the blower is blowing, and you can feel heat but very little coming out, but with high blower noise, I would suspect the blend door is not working correctly. I believe there is an electronic motor which controls the blend door operation. Maybe that is the culprit. These pics are all from a DC FSM, I can not explain the missing part numbers/pics.

Page 1 of 1	All times are UTC - 5 hours [ DST ]
Powered by phpBB © 2000, 2002, 2005, 2007 phpBB Group http://www.phpbb.com/