[greasemonkey]

Blend door actuator. It's been discussed here a few times, sometimes you can get lucky and reset them. There is a specific procedure for this if you don't have a Tech2. Others have been able to disassemble, clean, and grease them. Some people opt to just change them since they will probably do it again. The driver side blend door actuator is located under the hush panel (if equipped) towards the passenger side over the trans tunnel. It's 3 screws and a wiring harness to pull the old one out.