Hi! I've got a 2004 Ranger 4.0 4X4.....for some reason the air conditioner started blowing out my defroster instead of the vents. It went back and forth last summer, but this year it's all in the defroster. Any ideas what's causing the problem? Thanks, Angela

 

Unless your vehicle has electronic automatic temp control I would suspect there is a vacuum leak in the vacuum lines to the controls that are not working correctly.
The systems are generally designed to default to defrost when vacuum control is lost.

 

Thankyou!!! I'll give it a look!

 

Oh boy....what a mess....seriously need some schematics....this could be one I can't do myself.