When I actuate all solenoids they click. But, these two don't drop the vacuum as expected:

Blue/yellow - blend air valve (warm)
Brown - heater valve (open)

Has anybody bench tested this? Similar findings? Explanation?

See pic of setup below.

See attached pic

Attached Thumbnails

 

I did solve the mystery. I sacrificed this unit to learn how it works. Those two valves work in reverse. The air mix and heater valve solenoids have brass plugs in the end that normally receive vacuum. The black sponge looking thing in the other end filters the air and is open to the the environment. So to test these, you'd pull a vacuum on the "Y" on the air mix valves or directly on the top of the heater valve solenoid. (I.e. pull the long black vacuum line.)

I have the newer style switchover valve in the car. So now I know how to test these things. They are definitely not meant to be disassembled, BTW. I had to drill out a tiny rivet in plug housing. The circuits are sort of wedged in there and contacts are stamped in a way where being a sub mm off during reassembly would be a short circuit.