Hello all. I just purchased a 2003 Grand Marquis LS and it has Automatic Climate Control. I'm brand new to having a car like this with so many electrical controls and I've never had Automatic Climate Control, so please forgive my ignorance. My problem is the thumbwheel that controls the fan speed.If the car is running and the air conditioning is turned off, moving the thumbwheel turns on the air conditioner. This doesn't seem to be logical to me, as it's only a control for the fan speed, not an on/off switch. Can any of you tell me if this is normal?

im guessing that it applies ac or heat depending on what the ACC calls for..

Hi Patrick, what is ACC? The fan speed control is simply turning on the Air Conditioner when moved. It seems to go into the last temperature setting it had before being shut off, which is usually for cool air. I don't know if that's normal or not. Is the fan speed control thumbwheel on the right side of the Auto Climate Control panel supposed to function as an on/off switch??

ACC (Automatic Climate Control)


Yes it is normal for the wheel to activate last setting. Even when you turn on the front defrost,you will hear the a/c compressor kick on,this is also normal. If you do not want the a/c to come on when you roll the fan wheel,you must choose a higher inside temp. than outside. Remember the ACC is a very nice feature,but it also affects fuel mileage. If you want best fuel milage,operate system manually. If you want creature comfort,use the ACC.


The thumbwheel doesn't neccesarily work as on/off switch. The ACC system will react a little slower if thumbwheel is not turned,but will still come on. Operating the thumbwheel only removes the delay in the system.

Thank you very much, Lenny. You've given me a great deal of peace of mind - I was already thinking there was an electrical short or something. I just purchased the car used and like I mentioned, it's my first time with so many features (I've owned basicentry level Toyotas for 20 years) - it was just first time jitters I guess. Thanks again, and have a very nice day.

as odd as it sounds, i am not a fan of the auto climate control..i like to decide when things go off and on...[img]smileys/smiley2.gif[/img]