This is what i did worked better than i thought it would. i pulled the dash, and inner dash to check all my blend doors. I found that my blend door for my defrost that is ran off the vacuum on the middle dial, the shaft had some how pulled out and the gear was not in the door. I fixed it. also didnt wont to pull the heater cole box, so i cut a hole in it just left of where u can see when u pull the glove box down. I was not only able to see the blend door for the heater/ac work, but i was able to put my hand on the face of the heater core. With my motor heated up I put my hand on the heater core, and it was not hot, but the hoses where. i have read a good deal on this. i have seen some people say the core cant get clogged up, and others say it can .It is a 99 and sat in the junk yard for a wile. when i got it it had the mud in the radiator. so i think im going to try to flush it out. also i put a clear plastic peace over the hole i cut so u can see the blend door move anytime u wont to. it worked nice so far dont leek a lot of air. To make the hole i used a razor knife and heated the blade with a pocket torch.