I have a question. The mode select actuator in my 2011 Expedition is clicking. Is there some way that would cause my AC to blow warm? I would think that the blend door would cause it, but not the mode select door. I hear the compressor kick on, but the mode select door clicks a few times and I don't get cold air.

The mode select door has been clicking for a little while, but the AC problem just started so I am wondering if there is any possibility they are related.

 

The outlet mode selection actuator(s) should have no effect on the temperature of the outlet air. Are you certain you have correctly identified the clicking actuator and that it is or isn't the temperature blend door actuator?

Have you verified that the refrigeration portion of the system is actually delivering cooling capability to the evaporator core? You may have two separate issues in the climate control system that need to be addressed separately. Or not... You'll need to make closer observations to correctly identify what is or isn't working.

 

Thanks for the reply. I felt the same way but here is what I can tell you for sure.
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• When I have the car running and I turn the temp from cold to hot, I can hear the blender door (behind the radio) moving and the temp coming out of the vents gets hotter. When I move it back to cold it gets less hot
• I believe the mode select door is by the gas pedal. I put my hand on it and feel it clicking. The clicking ONLY happens when I put the AC or MAX AC on.

Could the mode select be stuck in a position where it is blocking air flow from getting to the AC coils (like an outside vent mode) which is why I am not getting AC inside?

 

No. The outlet airflow diverter is set up so that air always goes somewhere. The mode selector is there to direct the outlet to where it is requested. However, if it's "clicking" it's likely got a problem.

It should get down close to ambient, just as if only VENT was selected, if the refrigeration system is not working. Does it behave that way?

 

That makes sense. I also forgot to mention that no matter where I divert it, it stays on the front facing vents. So if I put it to defrost it stays on the front facing vents. If I put it on floor it stays on the front facing vents. This further reinforces what you are saying.

Yes basically if I put it on cold it is ambient. If I put it on hot, I feel the heat. I did check the AC system and the refrigerant is at the right pressure levels and the compressor is kicking on.

 

Then you have two problems: 1) mode select isn't working and 2) the cooling function is not working.

 

Ok, question. If I had the AC on and turned on the heat, is there some sort of door that closes access to the AC coils and exposes the heater core? I am wondering if it is that door.

 

Not exactly.

All airflow, regardless of inlet source, is always routed through the evaporator core. The temperature blend door then adjusts to either bypass or send air (proportionally based on control setting) through the heater core for re-heating as needed.