Why is the A/C Light always on?

[G35autocrosser]

So when it is freezing outside and I have the seat heaters on and trying to warm the car up as fast as possible, should I worry about the A/C light being on. it doesn't make sense to me (except when you are defrosting the windshield) but I haven't seen any explanation in the manual or other places. Is the A/C actually running when you have it on forward vents (no defrost) and do you have to push the button every time to turn it off and be more efficient or does the light really not matter and it only uses it if it needs to cool the air? is there a way to get the default when you turn the car on or the temp control on not to start with the A/C on?

thanks.
Modified by G35autocrosser at 8:51 AM 12/22/2007

[adren77]

On the previous G35's, if the AC light is on, the compressor is working. This is really retarded, and you have to turn it off each time. It's probably the same with your car.

Push the AC button a few times and listen carefully. If you hear extra noise it's your compressor working, meaning the AC is working and you should turn it off if it's cold outside.

[Kendahl]

I gather you have the Premium package which includes dual zone climate control. In automatic mode, the AC indicator is always lit. I don't know if this means that the compressor is actually working or if it just available to cool the interior if necessary. To turn if off, just press the AC button. You will still be able to set the temperature but, if it gets too hot inside, the AC will not be available to cool it off. During cold weather, I run in this mode.

[G35autocrosser]

Yes. I have the Premium Package. I often turn the A/C off now (given it is below 40 degrees about 100% of the time in Cleveland), but sometimes I forget and it is annoying.

I am looking to see if anyone knows if the compressor is actually running and just can't believe there isn't a way to have it default so that it doesn't turn on in this mode if that is the case.

thanks for the response.

[redhed]

in auto mode below a certain temperature the A/C compressor will not run, but i'm not sure what that temperature is. in my g35 in cold weather i just hit the auto button and then a/c button to turn that off. the a/c button will stay unlit until i hit auto again.

but keep one thing in mind. it is a good idea to cycle the a/c occasionally even in cold weather because the flow of refrigerant helps keep the seals from drying out.

[Magellan]

in auto mode below a certain temperature the A/C compressor will not run, but i'm not sure what that temperature is. in my g35 in cold weather i just hit the auto button and then a/c button to turn that off. the a/c button will stay unlit until i hit auto again.

I experienced the same thing in my G37. I guess there's no point in hitting the A/C button to off if the compressor is not running anyway.

[redhed]

well, i've noticed my compressor running in temperatures as cold as the 20s...so to make sure it doesn't run you have to hit the ac button.

one way to tell if the compressor is running is to listen for the condensor fan kicking in. it's quite noticeable if you are outside the car.

[smark]

"it doesn't make sense to me"

If the climate control is in AUTO and the temperature is cold enough for the climate control to switch to heating mode, then if you turn off the the AC the windows can/will fog. And I think the climate control will no longer be in AUTO if you turn off the AC.

Please refer to page 4-26 of the owner's manual.

Update: When I got home from work I checked the AC operation. It worked as Redhed said - it stayed in AUTO when AC was off. However, if the AC is off and you press AUTO, the AC comes back on. I assume that if the AC is off and the AUTO light is on, and the temp is set low enough for the AC to come on, it probably won't. So in effect, it's not truly in AUTO anymore.

In my SC300 the AUTO goes off if the AC is turned off.

Where I live the windows will usually fog if the AC is off and the heater is on because it's usually not below freezing when it's cold enough for the heater to be on. Another thing is that if you have passengers in the car and the heat on without AC, the moisture released from the passengers can be enough to fog the windows.

Also, why is someone who is driving a 330 HP sports car concerned about being "efficient?"

Modified by smark at 5:27 AM 1/3/2008

Modified by smark at 6:13 AM 1/3/2008
Modified by smark at 9:15 AM 1/3/2008

[redhed]

if you hit the auto button and then hit the a/c button to turn it off (the a/c) everything else remains in auto mode (fan speed, temperature settings and mode selection), the only difference is the a/c compressor won't run.

where i live it is generally cold enough in the winter that the a/c doesn't need to run to get rid of excess moisture in the air...

[08G37S]

Modern cars with automatic climate control are designed to operate with the A/C on at all times to properly control the temperature AND humidity in the car. It isn't hurting anything to leave the A/C on. The whole point of the automatic climate control is you just set the temperature, hit auto and the car takes care of the rest.

[gr3gory]

hopefully this isn't considered a thread-jacking since it does relate to the auto-climate control.

i've noticed that when auto-climate control is on, the heat mode always defaults to the floor vents and never changes. is there no way to have the auto controls emit heat from the driver/passenger front facing vents without clicking over manually?

[adren77]

In my opinion infiniti's climate control is very poorly designed.

The AC should not be running at sub freezing temperatures. I don't know if they changed this for G37, but on my 04 G, if the AC light is on, the compressor is working and thus wasting gas. (You can tell this by listening, as someone pointed out earlier). If you turn off the AC button, the auto mode is still ON, which is a good thing, but I'm tired of having to worry about it all the time.

hopefully this isn't considered a thread-jacking since it does relate to the auto-climate control.

i've noticed that when auto-climate control is on, the heat mode always defaults to the floor vents and never changes. is there no way to have the auto controls emit heat from the driver/passenger front facing vents without clicking over manually?

no you can't ( I agree it's dumb)

[redhed]

from my experience the auto climate systems function pretty much the same from car maker to car maker. if you have it in full auto mode, the a/c compressor will cycle periodically unless it's too cold outside. i know on my car if the outside temperature is in the teens or colder...even in full auto mode with the a/c light lit...the compressor doesn't cycle.

[smark]

If you turn off the AC button, the auto mode is still ON, which is a good thing, but I'm tired of having to worry about it all the time.

no you can't ( I agree it's dumb)

What's dumb is many of the comments posted in this thread about "having to worry about it all the time," "have the auto controls emit heat...without clicking over manually", and "I often turn the A/C off...but sometimes I forget and it is annoying."

One would think some of you have to go through a ten page procedure to set the Climate Control as you want it to operate, and then you can't sleep at night because of it.

Set it to AUTO and turn the dial to the desired temp and forget about it.

Or if that's too much of a hassle for you, then you can say the command if you have NAV - oh, but you have to push a button.

AC on? - push one button to turn it off.

Heat not blowing in your face, push one button a few times.

AC running wastes gas? - buy a Prius.

Get a life and stop sitting around thinking of silly reasons to post on a board.

[pdrumans]

In Florida it still gets pretty cold (down in the 20-30 range last week) and even when cold there is a lot of humidity in the air. The compressor running in the winter helps to dry out the air in the car and defog the windows. We have to use the compressor.