The ac/heat temperature adjustment controls seem to work fine but the air volume control will work on 1, 2, and 3, but shuts off completely when you get to 4 or 5 on the dial. On hot summer days occasionally 5 will start working again but doesn't last long before it shuts off. Also, the right switch on the panel controls air flow direction. Only the floor and defrost controls work. If you move it to front vents no air comes out of the front vents. I can't determine if the air is still being redirected out of the defrost vents. If it is there isn't a lot of volume. Do i have multiple problems or is this something that can be fixed with new switches?
What year is your Envoy ? Probably high speed relay .
SOURCE: There is no air flow
You need part GM Part number 89018675 or ACDelco 15-73596. The Mode Selector Actuator. What happens is the part is a CHEAP part POORLY designed and when it goes to turn the flaps inside the HVAC unit its the plastic gear slips instead of turning the flap!!!
Just to forward you you might want a deal to install this art for you unless your good at fixing your own vehicle, because you need SMALL sockets and a lot of patience to get this part in!!!
The part is ALMOST directly above the steering shaft for your steering wheel, so theres a lot you got to remove before you will even see them!!!
I only recommend you to have a dealer put this part in for you, unless you have your own service manual!!
Because there is 5 of these darn things and if you pick the wrong one you will have to do it all over again!!!
3 on the Drivers side and 2 on the Passengers side!!
But replacing this part SHOULD solve all your problems!! AS it did for me and i was having the same issues as you have described!!
SOURCE: front panel temperature control switch
Very likely the blend door is broken. This door is mounted beside the heater core, blends cool air with hot depending on the position of the door. At the bottom of the door at the hinge point, there is a gear and coupling driven by an electric motor to position the door. The coupling is a drive much like a square drive ratchet and socket made of plastic and often cracks allowing the drive to turn without changing the door position. I've heard you can drill through the outer housing and put a screw in the door through the drive gear, but you would have to know your way around this area well.
I repaired mine by replacing the blend door, a big job at best. The entire dashboard must come out to access the top of the heater core housing which must be removed.
SOURCE: Vent control
You have a vacuum leak.Defrost is the default postion(no vacuum).
See if you can locate the small black vacuum line that goes inside the vehicle on the passenger side near the heater core. The trace it back,should see it going to a canister then to the intake manifold.Make sure it is not disconnected or broken somewhere.
SOURCE: heating / air conditioning control stuck to front defrost vents
There is a vacuum leak under the hood. Find the vacuum line on the passenger side where it comes through the firewall and follow it to the engine. You system needs vacuum to operate and without it the default setting is on defrost for safety reasons.
104 views
Usually answered in minutes!
×