Turn the heat on and motor idles rough but seems to want to accelerate?

[Uriken]

Hello gang. Im a bit new with this motor and still finding my way around the mechanics of this car. I purchased an 05 Aveo and after quite a few small repairs its become a cool little car. Its that time here in Ohio to get cold and the flakes have started flying so I have had the heat on a lot the last few days. I notice when I turn it on I can "feel" it grab and it picks up with acceleration if Im not stopped and at an idle it runs rough. Im thinking something to do with the AC compressor? Any thoughts?

[slayerized6]

An AC compressor, when on, would cause the engine to rev a little higher at idle because it is part of the accessory drive system.

But if you are using heat, make sure the AC button is not lit up; you dont need the compressor running for heat.

[Uriken]

For some reason the compressor is running when the heat is on. The AC button is not active. This car has had some wiring issues so I will have to see why this is coming on when turning on the heat.

[buvdog87]

If the defrost is on, the A/C compressor will turn on regardless. All cars with A/C will do this if the defrost is on.

[Eg.h2o]

If the defrost is on, the A/C compressor will turn on regardless. All cars with A/C will do this if the defrost is on.

yes. This ^ ^ ^

if you have the blower set to blow on the windshield, the AC will come on to help remove moisture from the warm blowing air. This is to help keep the inside of the windshield fog free.