I got a 92 suburban and the defroster don't work correctly, the motor that
moves the deflector is working but no air comes out the defroster vent, I
get a high pitched whistle so I think maybe something has fallen down in
there. Has anyone tore into the duct work under the dash or had this problem
before? I guess my question is, how and where do I start to take this apart
and find the problem?