What controls the heater-A/C blower directional setting?

Thanks,I found two small vacuum lines penetrating the passenger side firewall together. Both appear to run from the (plastic???) intake manifold and appear to be intact. I'll have to find a means to test them to determine leak. My skill level used to be pretty good, built and raced drag cars in the 60's. Little recent experience, never had to work on cars with "computers" controlling things.

That's plenty skill/savvy enough.... some don't have any business opening the hood!!.... Sad but it's the truth!!.. You may have to pull the control panel to test vacuum.

Thanks for your help, I'll see what I can do in the dash area.

Ok.... keep looking ... it's a leak somewhere!

Many thanks, Pushrod! I traced the vacuum system from the intake manifold, through the firewall, through a vacuum storage tank to the switch in the dash to various vacuum actuators. I couldn't find a leak. took each connection apart and reseated each tube. Started the Explorer and now it works perfectly! Apparently it was just screwing with an old man. (Obviously there was a leak somewhere but it wasn't apparent to me.) I really appreciate your help.

Glad you got it fixed!!! Thanks for the feedback...