No air coming out the defroster 1985 suburban

[Dead Parrot]

If the problem started about the time the first garage 'fixed' the vacuum hose problem, likely they missed reconnecting the round vacuum canister on the firewall that connects to the inside the cab climate control system. IIRC, the default no vacuum positions are bottom heater output and no recirculate.

Could also be that the 34 year old system failed about the same time but was unrelated to anything the first garage did.