Defrost causing idle problems

I am new to this forum. I have read many of the isues and recommendation for explorer problems. There are a lot of experienced people on this forum. I have a problem I have been trying to resolve for the past week.

I am having a problem with my 2001 Explorer Sport when idling in drive and the defroster position is selected. The engine idle fluctuates from 500 rpm down to 300 rpm. If the heat selector is positioned to blow air only at your feet the idle is stable. I have recharged my AC thinking that may be the problem, but because of the cold weather I am having a problem confirming the AC pressures.

Could this be a problem with the AC clutch or am I totally off base? Has anyone experienced a similar problem?

sounds to me like the ac clutch or compressor trying to lock up. my camaro done that and i had to get the ac serviced, it cured it.

Sounds similar to the problem I'm having. Only not quite as bad. When I turn on the defroster, the engine stalls.

Mine has been diagnosed as a compressor problem.

I am new to this forum. I have read many of the isues and recommendation for explorer problems. There are a lot of experienced people on this forum. I have a problem I have been trying to resolve for the past week.

I am having a problem with my 2001 Explorer Sport when idling in drive and the defroster position is selected. The engine idle fluctuates from 500 rpm down to 300 rpm. If the heat selector is positioned to blow air only at your feet the idle is stable. I have recharged my AC thinking that may be the problem, but because of the cold weather I am having a problem confirming the AC pressures.

Could this be a problem with the AC clutch or am I totally off base? Has anyone experienced a similar problem?
For now you can unplug your ac compressor until warmer weather so it does'nt come on and you have a smooth idle.The compressor is suppose to cycle on and off in defrost mode.

Do yourself a favor and visually inspect all your vacuum lines inch by inch. It sounds to me like you have a vacuum leak. Different positions on the Defrost/floor/vent switch (which is controlled by vacuum) put different demands on the vacuum system. Lift your hood and there should be a vacuum diagram specific to your vehicle somewhere in the neighborhood of your hood latch. Inch by Inch! beats spending money you don't need to.