Cadillac Repair: ecs, control actuators, vacuum problem

Question
QUESTION: My environmental control is acting up. Sometimes will only blow air out where defrost comes out no matter what is on. Will not turn air on. Blower on at all times even with engine off and key in off position.

ANSWER: Steve,
Most likely the blower module on the constant running blower, As for the vent issue, sounds like a vacuum problem. When "specifically" do you have the problem?

---------- FOLLOW-UP ----------

QUESTION: The problem with the vent occurs at different times. It will suddenly change every once in awhile but most of the time it blows out the defrost vent.

Answer
Steve,
The reason I asked is that if it only acted up while under acceleration, I'd say the vacuum reservoir had a leak. If it just does it sporadically, I'd at least check the vacuum line connections in the car, but also check the duct control actuators, and the programmer to make sure the vacuum signal is being properly applied.