1997 Ranger

[Eric M]

When my 1997 Ranger (5 speed, 4 cyl) has the A/C on max it will blow air correctly through the vents then it will redirect the air through the defrost vents. It will continue to switch back and forth on its own. What causes this?

 

[osranger]

Sounds like a vacuum leak in the diverter or the line to it. Do you notice that it goes out the defrost vents when you are accelerating? If so, thats the likely area to look at.