Problem with heater blowing cold air

[unforgiven]

We have a 2008 CX-9 Grand Touring that the heater appears to be acting up. Normally the heater is warm within a few minutes but when my wife drop it to work, it did not start blowing warm air until about 20 minutes later. The water temperature is normal and heats up fast as always. I drove it today and turned it up to 80 degrees and the fan started blowing hard as I would expect when turning the heat way up but the air was cool. When we started heading home later, it worked. Any ideas what I can check myself? Thanks for any help you can offer!

 

[RenesisKing]

I'm assuming you have the dual climate control and not a single climate control. My RX-8 does the same thing but I have single climate control (with the simple knobs) and I have to get a new HVAC control unit. It could just be the same thing. I would normally just say take it to the dealership but they're going to charge you a minimum of $90 to just diagnose it plus whatever it costs to fix it, and I know it won't be cheap.

 

[unforgiven]

Yes, I have the dual climate control. I have done some google searches and could not find anything specific to the CX-9 but I did see some similar posts where it was mentioned a control arm on a valve was sticking but I have not been able to locate it. I can see where two hoses come into the firewall and if I open the glove box and pull down the fuse panel door, I can see something behind the dash in the general vicinity of where the hoses come in that looks like some type of white plastic linkage. Lot's of white plastic everywhere so not sure what I'm looking at. I can't move it manually but I"m going to wait until tomorrow when the engine in hot and work the temp controls to see if anything inside there moves.

 

[unforgiven]

I opened the glove box panel tonight and turned the passenger temp adjustment from max cool to max heat and I could see the white plastic piece move as I changed the temp. If the temp was all the way up, it moved completely in one direction. If I turned it all the way down, it moved all the way in the other direction. If I changed the temp a little, it would move only a little. Appears to move in position respective to the setting. The heater was working correctly while I was doing this. Is this controlling the heater valve based on how it moves? It only moved with the passenger setting. Perhaps there is one on the other side for the driver controller I can't see.