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If this is an older vehicle the cable that controls the vent/def gate is broken or off. If this same gate is controled by a vacume servo or dashpot then the problem is either a leak in the vacume lines going to these accuators or faulty controllers themselves. Vacume leaks are sinister in that a bad leak far from your problem area can still cause a lot of problems simply by not allowing any vacume to build in the system
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2001 dodge 1500 ac and heater flow regulator switch does not work. works only on defrost?
2001 dodge ram 1500 ac and heater flow regulator switch does not work. works only on defrost. How to fix?
Heat flow will not change from main vent to floor or defrost 2000 Chevy s10?
Check under hood for a broken or disconnected vacuum supply line.
I have a 2002 Ford Explorer that is get low air flow from the defrost vent when the defrost unit is selected. Most of the air flow is going to the floor vents. Is the blend valve bad?
Hi, It is not the blend door, that is for heat/cold changes. The mode door could be the problem, or stuck defrost door.
Why is your car only blowing air at the feet?
If you can Not change the location of the air flow to the different outlets (defrost, dash, floor, etc) That sounds like a mode door problem or a mode door control knob.
Why won't the dash vents work on my 1995 Chevy Camaro but floor vents and defrost vent work fine?
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.
What to check for defroster on 1998 taurus that takes about 45 minutes to defrost; air flow strong; coolent level fine; air cabin filter new?
heater core may be partly plugged .
Where is the heater core valve on a 1997 chrysler cirrus?
It does not have a water flow valve in the heater plumbing.It does not have a water flow valve in the heater plumbing.
SINCE I HAD MY 1987 Nissan 300zx SMOGGED I HAVE NO VENTILATION FROM THE VENTS WHETHER I TURN ON ECONOMY-AC THE AIRS BLOWS OUT OF THE DEFROST VENT ON TOP OF DASH?
It sounds like your air flow diverter is stuck on defrost. Basically it is a little door that diverts the air fom vent to defrost to feet. It could be either the heater control valve, or te temperature selecter cable is broke.
What is the cause of 1995 jimmy with no heat coming from main vent Defrost is fine as well as floor heat When turned to cold side air flow increases When turned back to heat air flow subside?
I have the identical problem on a 1991 Jimmy. I have replaced the blower motor and flushed the heater coil. I know the vents are working properly because they work when the temperature is selected to cold. I am wondering if there is something under the hood that redirects the aif flow either through the cooling coil or the heater coil based on the position of the temperature control. If so possibly the heater coil (air side) is clogged. I noticed that the heater coil is below the AC coil so it is possible that debris is down in it. I may try to pull it and clean it. Have you tried that?
Why won't heater control change on 1987 Chevy Celebrity?
The most likely reason that the heater control won't change the air flow is that the cable that moves the diverter valve has broken and will need to be replaced.
What do you see when defrost heater of a refrigerator is not working?
The first sign you see is formation of some frost on the back wall of the freezer section. When you see this behind the wall where the evaporator is, there is already a lot of frost/ice covering the entire evaporator. This stops cold air flow to the fresh food section and causing it to warm up. Usually this happens due to failure to one or more of the following: 1. Defrost Heater 2. Defrost Timer 3. Defrost Thermostat Note: My answer may be specific to side-by-side refrigerators. Evaporator coil of other types of refrigerators may be located at a different place.
Why does AC and heater blow air through defrost vents and will not blow air?
depending on what year and make it is, the most likely issue is that you have a valve that moves to divert air to the upper vents, floor vents, and defrost vents and it is either stuck in the defrost position, is broken, or a cable/connector has come loose. The valve is usually in the center of your dashboard up against the firewall. The air flow direction in many vehicles is operated by vacuum controlled servos. If the vacuum supply is cut off, the system reverts to it's default position which is the defrost mode. My guess would be that the HVAC vacuum supply line under the hood is disconnected, pinched or collapsed.
