Mitsubishi Repair: blower switch, hvac control, blower motor

Question
my mitsubishi 2001 montero xls's blower switch isn't working properly. if you turn the a/c on and the light comes on but speed 1,2,3 doesn't work.  when you get to four for high the a/c shuts off and it blows heat. all fuses are good. do you think it is the switch and how do i replace it?

Answer
Ken,
This does sound like there's a problem in your HVAC control switch, your blower motor, or an issue with your A/C system itself.  I'd recommend you have a mechanic inspect the A/C system and confirm if the blower motor is operating properly.  
Good luck!