I have a 2005 Maxx with 75K, have owned since new. Recently the climate control system has gone whacky and will begin pumping heated air at the highest fan speed, no matter what temperature setting I enter. Even in shut-off mode (circle indicator on fan speed dial), warm air continues to flow through the system, though it can be directed to the different ducts using the right side control knob. Cycling the temp. indicator down to 60 and up to 90, then back down to a normal setting will sometimes correct the problem but only temporarily. Switching to manual controls has no effect at all. Anyone got an idea what's wrong here? My dealer's techs--geniuses that they are-- can only fix what appears as a code when they run diagnostics and I've not been able to make the problem occur when at the dealer's shop. Thanks in advance...
Dan in MD

If your trying to run the A/C it sounds like a lack of R134a. You've either got too little to cool down or perhaps too little for the compressor to even come on. The compressor has a safety feature that monitors R134a levels if there's too little or too much it won't allow the compressor clutch to engage.