AC blowing from defroster and bottom heater vents on my 83 pontiac parisienne. I understand it'* a vacuum line problem that doesn't close the vent. Can someone tell me which line is the culprit or where exactly to look for it? Thank you!

For less confusion, Please only create one thread per issue.
Let'* use your other main Pontaic Post for member replies.
Located here: https://www.gmforum.com/pontiac-168/...*-only-310336/
Thread Closed.