[Milo]

In certain positions of the climate control dial, the A/C automatically engages. Too sore to go out and get the manual right now. Is there a work around for this?

Example: The vent control is set to defrost, and the temp control is on full hot. Start the engine and the A/C light is on and I hear the compressor engage.

 

[TrevorS]

I've no idea about circumventing it, but I'm guessing the reason for it is that when defrosting, there typically tends to be moisture condensation on the inside of the windshield due to the interior/exterior temperature differential and our moist breath. The A/C acts as a dehumidifier, thereby preventing condensation. Usually gives a better result than wiping with your hand (which tends to smear and leave skin oils) or tissues (which tend to smear and leave paper debris).

 

[fotomoto]

Example: The vent control is set to defrost, and the temp control is on full hot. Start the engine and the A/C light is on and I hear the compressor engage.

Yup, you need to RTM. Defrost engages the a/c so it will provide dry, dehumidified air to the glass. This is not a Cube/Nissan concept.

 

[ChristineK]

To add, always turn off the AC before turning off the vehicle. Never leave the AC on. Well actually it is your car so do what you like but I recommend you don't.

 

[redbluff]

If you dont want the air on when the defroster is on just push the AC button. It will go off but defroster stays on but with no air conditioning.

 

[Milo]

LOL Bal. Thanks folks. Never thought about the "dry" air factor with the A/C. First time I've had a car with this feature (turn to defrost - A/C goes on). Will have to experiment and see which is faster, and then edumucate the wife (her Cobalt does not do this) if it's better.

 

[Square1]

Milo, regardless of weather you turn the A/C switch on or off the A/C will peridocally cycle on and off in any of the defrost modes. Like it was mentioned earlier, this is to lower the humidity in the cabin thereby lessening interior glass fogging. This is pretty much par for the course on any vehicle equipped with air. - Dan

 

[Square1]

To add, always turn off the AC before turning off the vehicle. Never leave the AC on. Well actually it is your car so do what you like but I recommend you don't.

This is a myth (sorry Christine), very old school practice that was used back when compressors were the old 6 cylinder style, or York "V" type (very heavy mechanical load), and before cars automatically shut off all accessories during start which all modern cars do now. The small R-4 type compressors in use today are much less of a mechanical load.

When you start your car, the air conditioning and main accessories are automatically turned off, so you don’t have to manually switch off the A/C or stereo before starting the car. These accessories are a big electrical draw on the battery if they're turned on during startup, and if they didn’t turn off automatically it could be such a large draw that the car may not be able to start. Next time you start your car, pay attention to the radio and other accessories, notice that they will turn off briefly when you crank the engine to start it.

BTW, I'm a certified GM A/C tech. - Dan

 

[ChristineK]

This is a myth (sorry Christine)

No problem at all, no one can be right all the time

But I still say turning it off is best practice, you are still placing load on an engine that does not yet even have oil pulsing thru its veins at full pressure yet.

I was told that info on my 1997 Mustang when the compressor went belly up in 1998.