if it's your re-circ door, you should read my previous answer sent below. Nonsense to everyone!!!! After reading several questions and answers and going to heatertreater.com, I narrowed down my problem to it being the Re-circ door. After seeing it would cost $120 for the part, I looked a little more and found out one option a person did on jeep forum.com. He simply removed the blower motor (3 screws) and reached up into the box. I did this exact thing and felt the re-circ door, which had broke and fallen, preventing air from getting into the cabin. I simply broke the door with my hand and pulled it out, placed the motor back up and in and YIPPEE!!!!! I fixed my problem. I never used the re-circ button anyways and don't think it will matter. I have 163k miles on my 2000 jeep grand cherokee limited and it took me about 10 minutes to fix the problem. I have been waiting for my mechanic (on the side) to figure out the problem for almost a year and I think ke's been blowing me off because of the same fear I had......nobody wants to spend a whole saturday trying to remove a dashboard! I can't wait to tell him I fixed it in less than 10 minutes. Again, a wonderful, inexpensive, stress free solution to your issue (little if any heat or ac blowing through your vents, even on highest setting). For those of you who think I'm nuts for completely removing my re-circ door, have fun paying your dealer $1400 or spending an entire saturday trying to take off your dashboard in between all the cuss words that will be coming out of your mouth. You'll remember this note quite frequently during your day of fun. While your removing your dash, I'll be hanging out with my family, watching NCAA college football and enjoying life!!!! Good luck and I hope many others read this and feel the same as I do right now!!!! Wonderful!! Problem fixed, no cash out of pocket, heat and AC working

where is the blower motor and 3 screws?

the blower motor is under the glove box, near where your passenger's feet. if you turn the fan on you can hear and feel it working. 3 little screws and you can acces the recirc door area. if the door broke, it will be loose and covering access to that area. break it and pull it out. Hope this helps.