recently i noticed that when i turn my AC on and crank it, the passenger side will only blow hot air, while the driver blows cool. i just noticed it when my girlfriend and i went for a drive, she kept saying how hot it was, while i was sitting there freezing, ha ha. I am just wondering what the problem could be? i took it into a dealership and they said it may be the control unit. replaces that ($240 later) and on my way to school this morning...i noticed it again, not too happy about that one, any suggestions?

 

Does your car have a control that allows heat on one side and cool on another? Assuming that it does, it probably is the control unit. I would rip out the dash and pull out the control unit. Look for any connections that are off or broken. You didn't post the year of your vehicle so that leaves us a little empty with options, but you can check E-Bay for the control module for your year. Also check out the local junkyards and see if they have a compatible one.