I have never come across this problem on the board before, so I figured I would post up to see if anyone else is having the same problem.

In the past 2 weeks, I have been using the heat in the car as the temps have taken a dump here. Anyway, at first I thought I accidently hit the ac controls, but it has happenned to frequently for it to be that. I am either losing my mind or having some sort of electrical mess up.

When the heat is on, at some point it will automatically switch over to A/C and recently I think one of the deforst buttons came on too. This never happenned before and just wondering if anyone else has had the same problem.

I already checked for TSB's and there were none that I can find.

Any takers?

 

I've had the AC light come on too while the heat was on. It seems to happen once you select the Mode to include front defost or once the outside temp is higher than the selected heat temp. One thing that bugs me is the heat can only be turned on with outside air, not circulated air. This option sucks if you're sitting in morning traffic with all these other cars that just started up. It smells like **** while you're freezing your *** off. Didn't Infiniti factor in real world conditions while programming this crap? All other cars I know allow you to circulate heat. It might not be default but you can turn off outside air and maintain heat.

 

ive noticed that any time i turn on the defrost, the a/c comes on. what the hell does a/c have to do with defrost???

 

The ac air helps defrost the windows

 

I've only had the car for awhile and it automatically comes up everytime the heat is on. From my understanding of how the system works the A/C keeps the windows from fogging up. While its primary duty is to remove heat from the inside of your vehicle. A secondary benefit is dehumidification.

 

I found a better answer on the web when I did a search:

Most auto defrosters these days engage the A/C compressor automatically. Not for the cooling, but for the dehumidification. If you just blow hot air on a cold window, the moisture in the air will condense and fog it up on the inside. So the air is first dehumidified by the A/C evaporator, and then heated by the heater unit. So in most cases, the defroster will impact your gas mileage the same as the A/C.

 

ohhhhh, makes sence. I guess you do learn something new everyday. Thanks.

 

I am not questioning the defrost feature cuz I know the AC comes on with that. My thing is that with the heat on, freezing my **** off, I'll go and look and see the AC magically turned on! WTF is that crap!!

Maybe Espresso's theory works in that the AC comes on if the outside air is higher. That seems logical, I'll have to pay attention more and see what happens. Just weird cuz I will have th ecar 3 yrs in March and never noticed it!

Thanx for the feedback guys!