MPV 2002. Black particles come out from air vents

your vent selector is stuck

are you talking about the overhead vents? They only recirculate air without the a/c on.

did you change your hepa filter? Buy ozium and spray in your vents.

When I turn on the heat in my 2004 mazda mpv the front air vents blow heat but the rear air vents are blowing cold. I have adjusted every setting is there something I am overlooking.

door for the evaporator/heater core is malfunctioning. common thing for the pins on the door to break off.

If they are stuck on defrost,then the problem is a little vaccum line that comes through the firewall as all the climate controls are vaccum controlled,so look for a small green or black plastic line unhooked.

you have a loss of vacuum. There is a small diameter black plastic tube from the engine compartment that feeds the climate controls. Check at back of control head, or there is a plastic connector under dash were other color tubes join to operate the other actuators of the system the black tube must have vacuum when engine is running. check under hood the black tube is spliced. separate the tube and check for vacuum The tube enters the firewall near the heater hoses.

Your ventilation shutter is not closing properly.

Just recently found this on my MPV. get on your back and slide just under the front of the van. just behind the bumper you'll see several holes about 3/4" to 1" diameter. there is one located more toward the driver side. there is a large black Phillips head screw. this should be the drain for the coolant/antifreeze. if you look inside under the hood, or through some of the other holes, you should be able to see where this connects to the radiator. hope that helps.