Handogen

Does anybody know why the AC led indicator automatically turns on when I put the climate control in AUTO mode?

Does it always kick in AC even when I'm heating the car?

What happens when the cabin reaches the desired temperature when cooling? Does the AC turn off, even though the light remains on?

In the interest of saving gas and not running the AC motor unnecessarily, I'm curious.

Hando

mooretorque

The A/C light remains on though the compressor itself is not always functioning, when the system is in AUTO. Actually, even if you've overriden fan speed and/or vent function (AUTO light will go off, A/C light will remain on). You can feel (barely) the compressor cycle on and off if sitting idling; it will not be noticeable when driving.

Only time A/C light is off is when you manually turn the A/C off.

spinteews

COOL, i learned soemthing new here.. i been doing auto but turning off AC since i thought it was killing my gas, but its automatic and lights just there to scare us drivers LOL

thanks torque

wwest

For purposes of cooling the A/C is not needed below about 55F, it can be helpful for dehumidifying the incoming airflow and thus helping to prevent or remove condensation from the interior glass surfaces. But its dehumidification capability declines precipetously as the temperature of the incoming airflow declines toward freezing at which point it is non-existant.

I was told recently, by a Porsche factory representative, that the ONLY reason the A/C compressor is "normally" operated at these lower temperatures is to "coat" the A/C evaporator core with a thin film of moisture which serves to supress the horrid mold and mildew smell you get when you first start the car up.

My 01 AWD RX will automatically engage the A/C compressor in defog/defrost/demist mode without lighting the indicator.

LexRX

I knew when I was an a/c question wwest wouldn't be far. Long time, no see - where ya been? Things have been real peaceful lately

Daddy-O

Quote:

horrid mold and mildew smell

I thought I smelled someone...I mean something.

Handogen

Thanks for clearing that up! I've been putting my system on Auto and turning off the AC as well. Old habits die hard!

I used to drive a Grand Cherokee Limited and spent $35 per fillup... so I was extremely conservative when it came to using the AC.

Hando