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Many cars use engine vacuum to operate HVAC controls. If vacuum is cut off the system defaults to the defrost mode. Check the HVAC vacuum supply hose under the hood leading from the engine. It may be disconnected or damaged.
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Why does ac and heater on 2000 f350 blow air through defrost when another position is selected ac clutch clicks and air still only blows through defrost?
You have vacuum line leaks somewhere.
Why 2005 Dodge stratus heater ac clima control blows hot air all the the time and when set to defrost it blows straight when set straight blows to the defrost?
You either have a bad controller or a bad actuator.........
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?
What would cause high pressure in a 1997 Dodge Ram ac system It started cycling on and off when the heater was on during the winter It currently blows warm air?
The systems AC system will run when the defrost is turn on.The manufactor does this to remove humity from the air making it easier to defrost the windsheild.The AC system should only run when the defrost is on though.If you are experiecing a high pressure promblem when the AC is running it is pronbly due to a overcharge of refrigerant.
2001 Chevy luminia car ac blower only blows on defrost why?
Faulty Function selector switch. Consider replacement.
Should ac compressor stay on when heater control moved to defrost in a 2000 durango?
Yes, the ac will run in the defrost position to dry the windshield.
What could the problem be on 1988 Ford Aerostar when AC blows air out dash vents and floor but heater and defrost do not blow any air at all?
A vacuum leak, or one of the doors is sticking/bad vacuum motor in the heater box.
Ac works but heater blows cold air?
heater hoses might have been disconected
Why does your 03 avalanche ac continue cycling with heater on?
it should if you have the heater control in the defrost position this is to remove the moisture from the air
Why my 98bonneville ac blows only through defrost but not through vents please help.i checked all fuses?
Because your battery terminals are rusty. Have your dad clean them, and then check it again.
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.
Is it normal for ac compressor to come on and go off with the heater on on 2002 dodge ram?
Yes, it will run when in defrost or mix.
