Vacuum Lines. I had the same problem and it was due to cracked vacuum lines. Listen for some hissing under the hood and you might be able to find the source of the problem. Mine was right around the battery....................As this may be the problem your should first check under your passenger side right under the glove box you might have to take a interior trim plate and you can check the door a vaccum door and manually move it and you can get air out of your window defroster and possiblt getting it switched over and get it working if not you have two actuators there you can get replaced.
does fan door motorized or on a vaccuum line when you switch from AC to defrost?
If you feel no air blowing at all (when you are not moving) then your fan is not blowing. If it is blowing air, and it is cold, when the heater is on, then most probably your heater core is leaking, or is clogged. These are easily replaceable and go bad all the time in older cars.
The fastest way to defrost a windshield is to turn the defrost vent on without heat or simply open the windows. Another option is to warm the inside of the car by turning the heater on.
no heat to front window went defrost is on
on the dash below the windshield.
That means either you have air in your heater core or your heater core is being bypassed
No, it is not safe to drive with a frozen windshield. It can obstruct your view and increase the risk of accidents. It is important to fully defrost and clear your windshield before driving.
Yes, the ac will run in the defrost position to dry the windshield.
Start driving with your air conditioning on defrost, the AC will defog the windshield but you need to be moving.
When there is a problem in the vent system it defaults to defrost setting. Check the doors & vac supply
The defrost function simply directs air over the inside of you windshield. It's temperature is controlled by the temperature dial on your environmental controls.
The AC on a 1998 Dodge Ram 1998 will only be blowing out the defrost vent if the air handler is not set properly. This can result from a piece of debris getting stuck or a faulty flap.