1982 Monte Carlo 267 v8. Heat flows through the floor and defrosters. have the dash out for easy access. seems there is absolutely no vacuum in the lines. in the engine compartment i see two lines, white to the vacuum ball and a black line to the heater hose valve, took the white line off hear a hissing from the ball, took the black line off no noise. also, another two lines i saw were gray and purple near the kick panel area that go through the firewall but don't see them in the engine bay. other details the cold air and hot air work fine as well as the fan speed resistor. blows excellent air out. any ideas where to go from here?

 

I have the same issue.. i see no one answered this yet... dang it.

 

Those actuators are all vacuum controlled. If it were me I'd pull a vacuum on the one line to see if it flips the actuator (that way you know the actuator itself is working properly) and then work from there to fix your vacuum issue.

I found this image online, it was labeled for an 82 cutlass but my understanding is the vehicles are very similar so it might be of some use to you.

 

thank you i hope this helps out.