OK, here's what is happening. When the car is cold, as in the morning - as opposed to sitting in a hot parking lot all day - the fan will blow high for a couple minutes when max is selected, then slow down to nothing. This occures whether A/C is selected or not. It will blow cold for this short time if A/C is selected. It still will not blow cold for a long while when hot (afternoon).
Does this sound like the temperature control unit?
Thanks,
Jacob