Auto Repair Q&A



Cooling System










Auto Repair Products

Where is the actuator blend door for a/c on 1999 6 cylinder Camaro? Air only blows thru dash and floor

follow ducts to where they

follow ducts to where they all connect and you will have to remove them to access the door.

This vehicle has vacuum

This vehicle has vacuum operated actuators located on the blower housing assembly--under the dash. The two actuators that you should pay close attention to are the one with the PURPLE vacuum hose attached to it (operates the bi-level blend door) and the one with the RED vacuum hose attached to it (operated the vent blend door). You'll have to get your head under there (with a flashlight) to find the ones in question.

These actuators are simply vacuum diaphragms, which move the blend doors when vacuum is either applied to them (causing them to open the blend door) or when vacuum is taken away (causing them to close the blend door).

There are four actuators in all, check the operation of these (the one with the ORANGE vacuum hose and the one with a YELLOW AND a GREEN vacuum hose) by turnng the selector knob from defrost to heat and watch how they move or react (engine should be running for this test). Now turn the selector to vent or bi-level and watch the purple and red ones to see how they react.
If no action, pull the vacuum hose off (one at a time) and check for vacuum at the hose with the selector in the bi-level or vent position (whichever one goes with the actuator you're testing at the time).
If no vacuum is present, check for a hole in the vacuum hose from the actuator to the a/c-heater control panel on the dash. (these vacuum hoses connect to the control panel)

If all of these checks are fine, then suspect a stuck blend door, which is located inside of the blower housing. you may have to take that apart in order to get to the blend door (sometimes you can get your hand into the housing and manipulate the door back on track).