Vents in middle and side are not blowing out air.vents by windshield are... Can

You have a vacuum leak under the hood,probably one of the small hard plastic hose(s) that come through the firewall. when this happens,the blower defaults to the defrost mode.repair,fittings,connectors available at parts stores,easy fix.

IF you don't have any luck with this repair - I'll be at Franklin Tire Distributors Tuesday for awhile doing some troubleshooting .. be happy to check it out for you. Located at - 1165 Old Forge Road, Callaway VA. It's in the phone book - talk to Earl or Brad.