My heater on my 2002 Ford Expedition blows out the defrost vents but not my front vents. What would cause this?
Wednesday, December 29th, 2010 AT 10:03 PM
1 Reply
JACOBANDNICKOLAS
MECHANIC
109,709 POSTS
Check for vacuum leaks under the dash. The vent doors are actuated by vacuum. If there is a leak, this will happen. When checking, start the engine and listen. If you are lucky, you may hear a hissing sound where the leak is located. NOTE: Make sure to do it in a well ventilated area.