Air conditioning cool/warm lever migrates to middle

I don't know what type of chassis you have so it's hard to make suggestions regarding the repair of the blend door. Most of them are pretty easy to fix without removing much of the dash and ducting etc. I would suggest you join a chat group that is about the chassis you have. Most Bs and Cs have factory HVACs.

That's how I fixed my F150, now to fix the DW's explorer.