Where is the defroster located in an air conditioner?

The defroster is part of the heater and air conditioner system which is housed inside of the heater plenum. The vent control system for the defroster in integrated into the operation of all temperature controls and uses forced air provided by the blower motor.

Why is my defroster not working on my car?

A control switch on the dash can fall apart allowing the vacuum to escape and not reach the servos. A defroster can also fade when traveling up a hill but then return once the grade is overcome which is a signal the vacuum check valve has failed.

How does the air vent work on a defroster?

The vent control system for the defroster in integrated into the operation of all temperature controls and uses forced air provided by the blower motor. On newer cars the vent direction and temperature controls are operated by a series of 3 or 4 electrical actuator motors which are adjusted by the climate control module.

How does the climate system control the defroster?

The climate system is responsible for controlling the position of the defroster actuator which is connected to the air position door in the heater plenum. This actuator controls defrost, middle and lower air vents. When it fails it can do so in the defrost position and must be replaced.

What causes air vents to stay in defrost position?

If you have an older car then the defroster system is controlled by using vacuum supplied by the engine. Lift the hood and inspect the vacuum hose or tube that leads from the intake manifold to the passenger’s side firewall. The image below shows a typical line break which causes the vents to stay in the defrost position.

Why is the TEM switch stuck in defrost?

Fan motor works fine, Tem switch works fine, but the other is stuck blowing out in defrost no mater which vent you turn to. I am trying to determine if it is the HVAC control module or the MODE actuator? before i buy any parts. Dealer wants 110.00 to Diag truck. Wants 1.5 hr labor to fix it, and the module is 324.00 at the Chevrolet dealer.

Can you turn the defrost knob back to feet?

I can turn the knob to defrost, then it springs back to feet/defrost but still only comes out of the front dash vents. I can turn the knob to every other setting and the knob will stay there but no matter what it only comes out of the front dash vents.

Can a car defrost when the heat is on?

I can turn the knob to every other setting and the knob will stay there but no matter what it only comes out of the front dash vents. The fan speed works fine, and the heat and A/C both work great. I’d really like to have defrost now that it’s winter.

Where does the vacuum line from the defroster go?

Vacuum lines travel from the vacuum control switch on the dash to vacuum servos under the dash. These servos move the air doors which turn on and off the defroster. If you can hear a hissing sound when the car is running from under the dash then vacuum is escaping.

Why is HVAC mode not working on my Durango?

Turning the knob one way or the other does not work becasue all that does is make the HVAC controller go to the position that it learned. Yes the temp dial was working but the mode did not. It generally blows out the defroster but actually some air comes out of all the vents.

Why does my Dodge Dakota only blow out defrost vents?

97 Dakota all of a sudden started only blowing out the defrost vents on all position settings. Anyone have a vacuum diagram or suggestions on how to track this down?

Where can I get new HVAC hoses for my Dodge Dakota?

You can get a new set of hoses for HVAC from dealer (will be color coded). I have a 2002 Dodge Dakota – 3.9 L and in June of 2007 I had only air coming out of my defrost vents, so I had the vent control motor replaced and it was working great, until about a week ago now the air is only coming out of my defrost vents again.

What’s the problem with my Dodge Ram heater?

Symptom 2 – Luke warm heat when set to 100% hot. Symptom 3 – The faster I turn the fan up the colder the air coming out gets.

Is the Dodge Dakota air conditioner factory affiliated?

IT MIGHT NOT BE THE WAY THE FACTORY WOULD ADVISE YOU TO FIX IT, BUT TI’S VERY INEXPENSIVE AND IT DOES WORK This site is in no way affiliated with Chrysler or any of its subsidiaries.

How does the defroster system work on an older car?

Why does my Mazda Protege heater only blow out front vents?

Eighth generation of the Mazda Protege. Heater only blowing out front vents, no heat to feet or defrost. Why? Heater working but only blows out front vents. No heat to feet or defrost.

Why does my GM Truck have no heat in defrost?

The defrost clears the windshield but it gets real cold in the cab. I have heat out of the upper vents in recirculate but when I flip to defrost and the truck flips over to fresh air its like the heater core can’t overcome the cold vent air. I have heat on both heater core lines and plenty of heat in recirculate mode.

Why does no heat come into my cabin?

Possibly a bad thermostat, a clogged heater core, or a faulty valve. Have you tried replacing the cabin filter. If it has been a long since you have done this, maybe it is very dirty and clogged. Just a thought.

When do you have no heat in defrost?

When driving on longer trips I have no heat in defrost. The defrost clears the windshield but it gets real cold in the cab. I have heat out of the upper vents in recirculate but when I flip to defrost and the truck flips over to fresh air its like the heater core can’t overcome the cold vent air.

Why is my heat vent stuck on one position?

The A/C-heater control module must be recalibrated each time an actuator motor or the A/C-heater control is replaced. If the vehicle is so equipped, the calibration procedure also includes rear HVAC positions for each actuator motor.

Why does my heater not change from defrost vents?

Re: Heater/ac will not change from defrost vents to any… Failure of mode and/or blend door operation most often tends to be vacuum supply issues. If there is no operation of the doors at all (switching from defrost-floor-vent) then verify vacuum supply on the vacuum line at entry of the firewall (it’s easiest to get to).

What to do if your Ford vent control is stuck?

Ford Vent Control Stuck on DEFROST? Here is how to FIX it. Simple Hack to save Money! – YouTube

What causes a defroster door to get stuck?

In some cases an electrical motor can burn out or the gears inside the actuator can break causing the defroster door to get stuck. A climate control system can stop working after a battery replacement as the control prompt of the system is lost and needs to be rebooted by removing the defroster/heater fuse for a period of time and then reinserted.

Why does AC blow cool air through defroster vents?

No matter what setting it’s on, or speed, it all comes out the defrost vents. So if I turn the AC on it will eventually blow cool air through the defroster vents while I’m driving, if I come to a stand still the AC air coming through the defroster vents will not be as cool, more musty.

When does a Ford car default to defrost?

It defaults to defrost when the motor/vacuum that turns the vents fails. Its vacuum controlled. The vacuum lines are under the hood, but I have no idea where. Passanger side fire wall over the valve cover. Black cylinder with a plastic nipple.

Why is my Ford F-250 stuck in defrost?

The suction system not only controls air zone valves, but also 4X4 activation. Typical vacuum leaks, like old lines are often the problem, but there is one last component that everyone participating on automotive help forums fails to mention when troubleshooting this trouble prone system, the electric vacuum solenoid valve. Loading…

Why is my a / C only blowing out of defrost vent?

Check the vacuum control valve on your heater hose. It is right next to the oil filler located on the heater hose. Make sure the gray vacuum line is hooked up to the front of it. Same Problem here, I checked all the lines and they all seem good, So I changed out the VAC Pump and Now it will move From Defrost to Floor but still no vent.

Where is the throttle valve on a Lincoln Towncar?

The throttle valve in the throttle body is completely closed when the throttle is released. The throttle valve would need to be automatically moved to the open and closed position continuously to control the idle.

How long does it take to replace IAC valve in Lincoln Towncar?

Start the engine and allow it to idle for two minutes. Raise the engine rpm up 2000 for one minute and allow the engine to idle. Put the car in gear at an idle and allow it to idle in gear for five minutes until the computer sets all the parameters again.

Where is the defroster located in an air conditioner?