You have a vacuum leak causing your vents to switch from dash to defrost.
The turn signal flasher switch is mounted on the steering column left side. The hazard light flasher switch is is the red triangle mounted on the dash dead center between the A/C vents.
Mode switch is for the climate control. It allows you to direct the airflow from your feet, to the dash vents, defrost etc.
If the heat selector will not switch from defrost to the dash or foot vents on a 1992 Buick, it is possible that the cable connected to the vent is broken. When the selector is moved from defrost, a cable opens the other selected vents on the heater.
Remove the vents and screws under the ac cluster speedometer cluster.
You either have a bad selector switch or a bad vacuum hose at the rear of the engine.
Does air come out at defrost vents? Defrost is the default position. Check for a vacuum leak either under the hood or under the dash Check the operation of the vacuum actuated motors under the dash Check the operation of the selector switch
this one is easy your switch the controls the vents is not working there is a flap the closes the defrost vents so that it goes through the other vents or there is a vacumn line that is controlled by the switch, and its leaking. The vacumn line is usually on the engine side of the firewall. It is a very small plastic tube comming out of the middle of the firewall at the top and it connects to a junction with other vacumn lines. See if any of them are disconnected.
it would depend on the year of the accord. Does the defrost work or the heat in the floor work if so the line for swapping control is either broke or has come off. you can check the lower side by looking in the drivers side under the dash.
Check for a vacuum leak either under the hood or under the dash Check the operation of the vacuum actuated motors under the dash Check the operation of the selector switch at the dash
If the climate control on a 2003 Trailblazer will not switch from feet to head vents, try changing it to defroster then back to head. The mode button on the dual climate control model can only be switched from face/feet to feet and then to defrost. The feet and head vents worked at the same time.
The doors are electric. You most likely have a broken door inside the heater box under the dash.
Check for a vacuum leak either under the hood or under the dash Check the operation of the vacuum actuated motors under the dash Check the operation of the selector switch Defrost is the default setting for this system
ITS THE VACCUM ADVANCE WHEN YOU ACCELERATE THE VACCUM IS LEAKING WHEN YOU RESUME SPEED THE A/C REACTS NORMAL CHECK VACCUM HOSE LEAKS
When there is a problem with the vent system it dfaults to the defrost setting. Sounds like you have a problem in the doors that direct the air flow.
Most likely a bad or disconnected vacuum hose to the defrost/floor selector in the heater ducting.
When there is a problem in the vent system it defaults to defrost setting. Check the doors & vac supply
The mode door actuator has failed. We have instructions for repair at www.trailvoy.com
the middle vents only supply air from the ac unit using a separate in dash fan. the floor and defrost vents come only from the heater
Over time debris and other things can collect near the heater core, its possible that something small and plastic has fallen down through the defrost vents and gets hot when the vehicle is running. You may need to disassemble the heater and remove the items and perhaps vacuum it out.
the ducts can not be hooked up for the vents to work
2003 crown vic air conditioning vent dont blow
That's probably steam from a leaky heater core.
on your car it is a defalt mode for air to blow out defrost when there is no vacumn from the engine so you should look for a broken vacum line or see if it has come unplugged on the engine.