What kind of car is is it? Without knowing anything else, I would suggest checking the fuses and relays. It should be the same blower; does it work with the heater? If so, it could be an issue with the a/c - heater control in your dashboard. It could also be a bad blower. If you can get to it, you can check to see if there is current going to the blower with a mulitester. If there is, and it's not on you know it needs replaced.
Bearing in blower motor?
Check the fuses.If not the fuse, test the resistor down by the blower motor.
you need a new blower motor resistor
where is the rear AC blower on the Chevy Astro 98
Blower motor, resistor, wiring or control problem are common causes
Check if the blower motor is working, and you will need to check the pressure in the AC line.
gants, I have Denali 2004, the rear AC blower not working
bad motor or capacitor
What about it?
I would like to know, where the ac blower is located on a 1999 BMW 528i
blower fan location on a 1979 lincoln
Did you check with OBD ? Maybe the problem with AC clutch relay. I have same problem with my 1993 Grand Cherokee Limited, and I bring to my mechanic and fix, because the connection on AC clutch relay relist. Hope can help