Originally Posted by
Top_Fuel
I've often wondered how the system actually works. My philosophy is that I want the HVAC doors to operate as minimally as possible...because the more they move, the more they are likely to fail over time.
So I never use the AUTO setting, I always have the air coming out of the dash vents, and the temp is always set to 89 in the winter. I assumed this would always keep the blend/mode doors in the same position...with maximum airflow over the heater core. I have no idea if this is actually how it works or not. The service manual can be frustrating when you want a text explanation of how something like this works.