0
Not knowing what vehicle you have, many vehicles use a vacuum supplied by the engine to operate the different positions for the air to come out. When the vacuum is absent the system defaults to the defrost mode. I would check the vacuum supply hose starting at the engine for cracks, damage and disconnection.
Wiki User
∙ 10y ago
Add your answer:
Earn +20 pts
Why would only cold air come out of the vent when you put on the heat or the defrost I have checked the panel switches that does not seem to be the problem?
AnswerCheck your heater core, do you smell antifreeze at all?no
Can't find the engine coolant temperature sensor on your 96 grand am 3.1 cooling fan not coming on only when air's on or defrost?
There is a sensor located at the bottom of the coolant reservoir.
What Reports are available on 1996 Oldsmobile regency 98?
RE: 96 OLDSMOBILE 98 REGENCY ELITE, V-8, 3.8 WHAT PART NEEDS TO BE REPLACED SO THE A/C AND HEAT VENTILATION WILL BLOW OUT OF THE FRONT VENTS AND NOT ONLY THE DEFROST?
How do you fix 97 vw jetta gls power windows only the front passenger side works?
I have a 97 volkswagon jetta gls 2.0 and three of my power windows do not work. Only the front passenger window works. How do I fix this problem.
Does the gh3 no fail cheat wor in career mode?
No. It only works in Quick Play Mode
Why is your air conditioner only coming out of the defrost in the car?
It have battery
Why does Air conditioner work on defrost only and no front vents or floor?
Vacuum leak
Why does the heat air conditioner defrost etc work but only if the fan is in the 4 position. No fan at all in the 1 2 or 3.?
You need to change the blower resistor, located behind glove box.
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?
Why would a 95 Ford Explorer AC cyle on and off when the switch is in defrost or heater position?
On my 1995 Ford Explorer when the defrost position is selected , and the temperature knob is set in the red area to get heated air to defrost the windshield , the A/C compressor will cycle on and off to help dehumidify the air, but the compressor ONLY cycles on and off in the DEFROST POSITION ( sorry if I'm misinterpretting your question )
S10 Blazer Air conditioner is not working the switch on the dash that controls the system doesn't seem to do anything stuck on flowing air out the windshield defrost only?
Check the vacuum supply from the engine. If it is disconnected or cracked the system will default to defrost only.
Why does 2000 Buick Lesabre Custom Air Conditioner blow only through defrost vents?
The vacuum supply line from the engine is disconnected or broken. When the vacuum supply is cut off the system defaults to the defrost mode.
Is the air conditioner fan on a 1996 Chrysler sebring supposed to run all the time?
no, only with defrost or ac on or if coolant temp is hot enough
The AC only comes out the defrost and out the Bottom.How can I make it come out the vents?
There is most likely a vacuum leak on the line from the engine to the air conditioner control.
Why does the coolant fan in a 1994 Saturn only come on when the air conditioner is on?
Cooling fan is designed to come on only when A/C, defrost, or engine temperature exceeds 235 degrees
The air conditioner only blows through the floor and defrost vents on a 2003 Saturn L300 how do you fix this?
Many HVAC systems operate with vacuum supplied from the engine. If the vacuum supply is cut off the system goes into default position which is floor and defrost. Look under the hood for a small vacuum line from the engine leading into the firewall that is damaged, cracked, pinched or disconnected.
Why does the air blower work only on high on your Jeep Cherokee sport 1999 also the selections swith for feet upper area and defrost only works on defrost and off?
Most likely it is a resistor that has blown on the back of the controls.
