I have a 01 Jeep Wrangler Sahara, and the air conditioning stopped working yesterday. It started with the third fan speed not working, and then stopped blowing any cold air. While driving, cold air will still creep through the vents very slowly, and I can still adjust the temperature. I checked vacuum lines on suggestion, and looked at the fuses, both under the hood, and behind the glove box, but could not find any problems. I've read it could be a problem with a blower resistor, but I'm not quite sure what that is. Any help or direction on solving my problem would be appreciated.