Today I realized (even though I have had the JKU for over a year) that the A/C automatically comes on with both the defroster and the combo defroster/feet setting. Is there a way to disable it? I think its an absurd feature.

 

Yeah, I've been wondering that too. Every other vehicle I've driven in recent years will have a "quick demist" setting where the A/C is activated however another setting which directs air to the windshield vents without the A/C being automatically activated is also present.

Apart from getting into the computer with a Scangauge or similar programmer and trying to disable it that way I'm guessing you'd need to remove the position dial from the dash & look at disabling the A/C activation switch that's fitted in there somewhere?

 

I've always been told there are two reasons for this:
1) An A/C system removes moisture from air. This less-moist air is what you want to defrost (remove moisture) from a window.
2) This a way to make sure your compressor get some action for the other 4-6 months of the year so it gets lubricated thoroughly.

That's my 2cents, and those reasons seem to be logical enough to comfort me...

 

No. And why is it absurd?

 

Even on a Honda Prelude, Kia sedona, Mitsubishi montero sport, VW Jetta and Nissan Altima with an "a/c" button, it still kicks on for defrost.
I'm sure all the rest do too.

 

There's nothing at all absurd about it. inside the windshield fog IS actually humidity...the A/C is also a very effective dehumidifier....The bonus here is that in doing so it helps keep the A/C seals moist and TIGHT, greatly reducing the likelyhood of a leak or premature seal failure. So what's so absurd about this?? I'd call it damn good engineering, but then what do I know anyway?

 

So the JKs without AC have decreased defrosting/defogging capabilities? The way I look at it is that there is button for the AC that is very easy to push. If you need to run the AC in order to defrost/defog, you should be able to push the button in order to turn it on. Running the AC compressor when not needed is not something I'd like to avoid (loss of MPG).

 

Every vehicle i've ever owned does this....its not "A Jeep thing"

 

I'm noticing (after much research) this is common now. My last vehicle was a 1994 didn't do this and my other vehicle Mini Cooper does turn it on for you automatically but you just push the button and it goes off. It's not forced. There seems to be other threads on other car/truck boards with similar questions on how to disable. Many have it linked via programming.

 

I have noticed all domestic manufactures will do this, and most foreign will not, or at least give you the option to turn off. My 86.5 Nissan (imported) gives you an A/C button to activate the compressor on any damper setting and never forces it on, while my 2004 Chevrolet Astro will activate A/C in Defrost, and split dash/floor setting. The forced A/C on is usually defeated when ambient temps are low enough to cause harm or inefficiency to the compressor. When it's that cold outside then heat should to be used to dry the moisture on the windshield anyway. Other than that, what other reason does anyone have to run the defrost? I do think it should be up to the operator to run your A/C comp when you want though.