No air blowing on any setting out any vent. rear works fine.

When you have heat on 4 and 5, but not on the others, replace the blower motor. especially since you have the noise. It is on the passenger side under the dash.

Mode door actuator . A electric motor that controls a door that directs air flow .

This model has a rear heat/cold blend door actuator. Its an electric motor that moves the duct door from hot to cold. When they wear out, they're usually stuck on the last setting

There is a separate button on the lower dash labeled RR HTR for the rear heater. If you do not engage the switch it will blow cold air.

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.

If this is equipped with a rear heater core it is probably plugged up and needs to be disassembled and cleaned out

well what I see you have two problems with you A/C ..1- if the compressor is cycling very fast , the system is probably low in freon , this ban takes like 4lb of freon, now, 2-if we have the right amount of freon and the rear A/C don't work and all the vents are working fine back there for sure the problem is the expansion valve located close to the rear evaporator , that valve get stock open allowing to much refridgerant get in to the evaporator and no cooling at all ,in the back,... you can also have a bad low pressure switch located on the accumulator, making the compressor cycling very fast ..the first you have to do is check the pressures if they are OK , change the low pressure switch..then go to the second problem

I have the 03 Expy with continuous rear air unit "clicking" or more accurately flapping of the air damper while the plastic gears in the 2L2H-19E616-AA grind away into toothlessness. Ford designed this unit to find the end of travel by jamming the motor to a stop and monitoring the current to determine when to stop applying voltage. That would probably be fine if the gears were designed to handle the jammed torque or the motor did not slip out of groove and continue turning and cracking the plastic gears.

There are two white colored boxes, one is for the temp plenum door, the other the upper/lower air flow. To be sure, do what I did, turn on the ignition, rear ac/heat and listen for the obnoxious click/thump as you move the temp control from full heat to full cool, you will know which part. Disconnect the electrical connector, four bolts and it is out!

Go to your dealer, part should be about $60 or less, look on line, lots of dealers sell for this or less on internet.

check you antifreeze level and make sure its full

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.