hi....newbie here. 2004 monte carlo. bought car in feb. a/c didnt work.
one day it started working...i was thrilled
i month later turn car offf...blower motor keeps running
new battery
i have to unplug blower after drivin...getting sore back
i live in cleveland ohio,,, its starting to get cold
now when i plug blower motor in...heat comes out passenger side ...ice cold a/c on drivers side

I NEED HELP
thanks kevin

 

sounds like the only think that could cause that many problems is the havc controls, which is what all your heater controlls are... why it happened, maybe the previous owner got pissed off and punched it... best way to test is a used unit. aside that, your fan saying on, could only be the relay under the hood has gone to crap.