not really worried about it...
I did have an odd thing happen today, any time I was under power on the fwy, IE climbing a hill, the blend doors changed and all of the air (a/c full blast) went out through the defrost vents. as soon as I crested said hill, or let off the gas and reduced power it went back.
not sure why.
also, I have a coolant leak somewhere. I can smell it in the cab, although its not overheating. I am thinking heater core.