I've got my dash out and thought I would figure out why I have trouble swithing between heater/vent, etc. Does anybody have any vacumn schematics that would help in figuring out what's not working properly?
Here's a guess. If it works, but just not as well as it should, the routings are OK, but you have a vacuum leak. Look closely at all of the lines, especially near the fittings to be sure none of the lines are broken or cracked and be sure that the vacuum cannister under the hood has good lines and does not leak.