I have a friend with an 94 legacy wagon that continually gets stuck in the defrost position.  I thought it was the control in the dash, but when we replaced it, the blend door stayed in the def position.  I got under the dash and pushed the actuator and all of a sudden it changed to vent.  It will change from any one of the setting positions unless you push the defrost and then it gets stuck in that position.  Is this a motor going bad or do I need to get in there and lubricate all of the moving parts?

 

Thanks

Likely just the motor going bad. Used should be fine. These don't seem to fail... Ever.

 

I've replaced dozens on Fords and Chevys and they are never easy. Not sure how the flaps are arranged on the Subaru. Hopefully you pull the screws out and the actuator pops right off.