Cabin air filter

Is this vehicle equipped with a cabin filter? And where is it?

When you look up under the dash to see the heater core. There is a black housing facing the passenger seat right behind the heater core. What is it. It has to do with the air flow when you set the ac on recirc? The little door that is conected to a vacuum thing is broken. I'm not sure what the part is.

I am getting warm air. But I am getting enough cold air in at the same time that I can't warm up the cab. Does the heater core housing have a small door on that is controlled by vacuum? The bracket where the arm of the vacuum attatches to is completely snapped off. So when you slam the door shut you hear this Little door flopping.

Thanx