I don't think I like the idea of the AC running when the climate control mode switch is set to floor. The winter is cold but dry here so I feel having the AC compressor running is an unnecessary efficiency penalty but I would still like to have warm feet.

I am considering disabling it by removing the fuse for the AC clutch for the winter. Has anyone else done this??

There is another purpose for having the A/C pump cycle during some modes of operation besides adding in defrosting.The auto makers figured out that during the winter months and the non-use of the A/C that the front seals in the pumps where roiting,so to prevent that and leaks they made the A/C cycle during the winter months to keep the seals all nice and good and leak free.

i use mine heavily for defogging during winter

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2007 Jeep Liberty XSport Competition Edition
Cragar Soft 8's
Alpine iDA-X300
Communications System Provided by: Cobra CB
Navigation provided by: Garmin

You never want to "disable" your AC for any lenghth of time what you need to do is run it every so often just to cycle it through like tjkj stated also

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MUDD'S MOTORSPORT'S We do IFS lift installs ,
03 OVERLAND EDITION /Kilby-Skidrow-Mopar-4XGuard skids/ 2.5 inch TOTAL CONTROL JBA coilovers -JBA Arms/MOABS-31 FALKEN WILDPEAK AT3W / 4.10's etc, 04 Kilimanjaro Edition loaded, plus 05 KJ limited

I wouldn't recommend disabling the compressor - it's a significant advantage in running the defroster - however
removing the compressor in the 'floor' mode was a popular thread

http://www.lostjeeps.com/forum/phpBB3/viewtopic.php?t=6042&highlight=compressor+settings

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2005 CRD
stuff
Skeptic quod gratis asseritur, gratis negatur

I have noticed that some people just want to tinker with their KJ's. They get bored and think "Wonder what this does?" and then they get themselves in trouble.

WHY WOULD YOU WANT TO MESS WITH YOUR AC COMPRESSOR?

Find something else to tinker with. Like your "Special Purpose" as steve martin calls it. and leave that thing alone or you will be paying larger repair bills later.

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'07 Ltd 3.7L, Black, OME HD's, OME shocks, Mopar Skids, AEV Bridgers w/ TPMS, Kumho KL78's, ARB Bumper, KC 130 Watters, Warn M8000 Winch, Rock Lizard Gecko Roof Basket KC 150 watters, Cobra 75WSX, 3 ft FireFly, RL Super Step Skinks

I agree with you sometimes I read some of these posts and think WTH, why do they want to do this, but then theres days when I just want to go out to the garage and "tinker" so

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MUDD'S MOTORSPORT'S We do IFS lift installs ,
03 OVERLAND EDITION /Kilby-Skidrow-Mopar-4XGuard skids/ 2.5 inch TOTAL CONTROL JBA coilovers -JBA Arms/MOABS-31 FALKEN WILDPEAK AT3W / 4.10's etc, 04 Kilimanjaro Edition loaded, plus 05 KJ limited

Ive unplugged it before in the summer so I could turn the A/C on which in turn causes the electric engine fan to stay on all the time. I dont use A/C when offroading but dont have the engine driven fan, so I do that to keep things nice and cool and to pull air through the tranny cooler at all times.

Ive never unhooked it in the winter though.

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LOST KJ'S
Where are you going???
Current Jeep: 2004 Jeep Liberty
-Atlantic Blue
-Air Ride Rear Suspension ; OME/Rustys Lift ; Powertrax Locker ; Moog Lower Ball-Joints ; 245/70/16 Yokohama Geolander A/T-S's on MOABS ; Flowmaster 50 SUV
Lost #007082
http://www.cardomain.com/id/jeepjeepster

You may not care but I would like to eek every ounce of fuel efficiency out of it. I already see a 10% hit in fuel economy during the winter months for the following reasons

- the AC presents a significant load to the engine while in floor mode which is almost exclusively the setting used during winter
- the torque converter won't lock until the tranny is warm which can take up to 20km when it's -20F out
- the diesel additives dilute the fuel

I can't do much about the last two but would like to be able to control the first

HMMMMM-----A $400 A/C pump(plus install and recharge another $200+) or 10% loss in mpg's for a few month's?




I'll go with the 10% loss of mpg's,but that's just my opinion.Have you thought about putting the HVAC controls on a setting that doesn't operate the A/C,like vent setting?I never use the floor setting,I like the hot air blowing on me not cooking my feet.

If you do unplug it, it wouldnt be a bad idea to use it at least once or twice a month for a few minutes.

We just bought a compressor for one of jeeps for $150 tjkj. Freon was free for us though.

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LOST KJ'S
Where are you going???
Current Jeep: 2004 Jeep Liberty
-Atlantic Blue
-Air Ride Rear Suspension ; OME/Rustys Lift ; Powertrax Locker ; Moog Lower Ball-Joints ; 245/70/16 Yokohama Geolander A/T-S's on MOABS ; Flowmaster 50 SUV
Lost #007082
http://www.cardomain.com/id/jeepjeepster

i notice that my kj get warmer faster when i use either the floor setting or the floor and vent setting, so i would considerdoing the mod where the a/c dosent come on in floor mode. as far as MPG is concerned, in the winter, you can forget about that 18-20MPG; its cold, the engine has to do more like run a blower motor, the AC and the rear defrosters; some states use a different blend of gas so getting good mpg is even harder; if you drive short distances to and from work, you gas mileage really goes down the tube becasue the engine idles a little higher to get that cat converter up to its operating temperature and to warm the engine itself. id say that if you did disable teh AC, youd still see a drop in MPG of about 10%, which is about 4-6MPG.

_________________
2007 Jeep Liberty XSport Competition Edition
Cragar Soft 8's
Alpine iDA-X300
Communications System Provided by: Cobra CB
Navigation provided by: Garmin

I would say that I use the Defrost setting a good 95% of the time during the winter months because the windows fog up when I use it on the floor setting.

N

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The beauty of a 4x4 is that you can get stuck at inaccessible places
=================================

2003 Liberty Sport
Blue w/ Gray trim
3.7L 5 Speed Manual
235/70/16 BFG MT's
65w Phillips fog light mod
AmsOil fluids end to end
SkidRow Front armor
Standard Frankenlift I & Al's U A-arms

The cheapest I found for a new compressor(read "new") is $364.80 for the 3.7 and $372 for the CRD's.And compressors cost different amounts depending on what vehicle they go in.You can get reman's for a little less,and a dealer will charge way more.There not hard to change but the clutch is a pain unless you have the correct tools.

Here is another tip to save 10%,

DRIVE SLOWER

And as far as the -20 dgrees thing, What vehicle doesn't take 20 minutes to warm up in that temp?

You are nuts if you think that monkeing with your ac compressor will save you money in the long run.

If your window fog up all the time then you have other issues beside 10% fuel savings. Pull your floor mats up and carpets back and see if there isn't a nice red color commonly called RUST under there.

It boggles the mind that some people just want to tinker with stuff they know NOTHING about just to see what it does. Hey tjkj, can you get him a job in the army tinkering with supposedly defused land mines and other ordenance?

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'07 Ltd 3.7L, Black, OME HD's, OME shocks, Mopar Skids, AEV Bridgers w/ TPMS, Kumho KL78's, ARB Bumper, KC 130 Watters, Warn M8000 Winch, Rock Lizard Gecko Roof Basket KC 150 watters, Cobra 75WSX, 3 ft FireFly, RL Super Step Skinks

I wouldn't mess with it .... Years ago I used to run my a/c in the winter for a few minutes every once in a while to keep the seals etc lubed. You don't have to do that anymore with the way the defrosters work.

tjkj is right. Besides, for the cost of a compressor you could get good rock rails or something.

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05 BLACK KJ - 42RLE & NP242
Skids, Hooks, Bent Rock Rail, Lifted, A/T's, etc.
NY and PA and Florida ONF Special Custom Organic Trail Rash

In the face/floor setting the A/C doesn’t turn on, so I use this setting to save gas in the winter when I don’t need to defrost. Unfortunately, it is humid enough here in north Texas that I end up using the defroster quite a bit, which is greatly aided by the A/C compressor.

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William C Montgomery
The Truth About Cars
The Truth About Guns
'05 Sport 4X4, 3.7L - Black | Frankenlift II Premium, JBA KJ Lifted A-Arms 4.5 | Cooper Discoverer A/T3 - LT245/75R16, Load C

The vent selection the A/C will not engage.


Just on a side note mordern A/C pumps and cyclic clutches are pretty easy on a engine(not so much the smaller 4 bangers) and in all reality you should only be loosing maybe 2%-5% in mpg's while using it,if your loosing more then that you got a problem somewhere.

In the winter like others have stated your not going to get good mpg's anyway due to most places switching to different fuels,longer idle times(to warm up),and using 4wd more often(or fulltime).I personally will be looking forward to a average of about 5-10mpg's for the winter months.I hate scrapping ice off my windshield so I use my remote starter with the defrost on to clear it for me.I just accept the loosey mpg's in the winter but have alot of fun playing in the snow so I forget about it.