No air from defroster vent

[Blues Pwr]

My 1986 olds 442 defroster vents will not put out any air, it did work fine previously.
Air will only blow out of the front dash and heater vents, no matter what position the selector is in.
Need to get this fixed before cold weather starts, thanks for any suggestions............

[88hurstolds]

Vacuum vent selector manifold on the control head is bad.
This vacuum diagram may help diagnose as well:

[Blues Pwr]

Thanks, is this what you are talking about GM#16037778 and or Alt#36694, I found for $26.16 w/free ship. and made in US?

[88hurstolds]

Yes, thats the culprit, try www.rockauto.com