86 C10 climate control not changing possition

[72freak]

86 Silverado. New to me. The fan is working and the temp control is working but it will only blow out of the face vents. Wont change to floor or defrost. Is that a vacuum line? Any hints on where to start to save me from tearing into the entire thing?

[Just call me Sean]

Yes, vacuum. Start by checking the feed under the hood.

[INSIDIOUS '86]

Blender door clip can be broken or the vacuum line to the motor isn't connected be the firewall

[Jake Wade]

Yes, that blend door plastic piece is well known to break.

[motornut]

1.if the rods are ok
2.check white piece that breaks is behind the glove box

[72freak]

Thanks for the info guys!

It was in fact the feed under the hood.. The small hard plastic vacuum line that comes out of the firewall beside the heater box was broken. Easy fix. For those having the same issue, I would start in the engine bay first when trouble shooting this especially if you have been doing engine work prior to the problem. That line is hard and brittle. Make sure you hook it up to constant vacuum. If that doesn't work then head inside under the dash and stand on your head.