SO I took the dash off and found that the blend door was stuck OPEN and the actuator works fine. This is the exact opposite of what normally happens, as the blend door defaults closed.

I tested the vacuum T to make sure the rubber hasn't shrunk around the soap stone inside to where it couldn't bleed off vacuum anymore, but it tested fine.

What I know: The vacuum to the actuator is constant there is no way to shut it off.

What I want to know: Is this the switchover valve failing and causing the constant vacuum, or is it the push button unit where the temp wheel is located failing? Every function on both items works perfect except being able to stop vacuum to the blend door to let it close..