Ok so I have a 87 GN trying to get this air to blow threw the vents instead of defrost . Changed out the vacuum switch yes it was in two pieces.no air coming thru vents. Check disconnect behind glove box plug was disconnect . So I got excited but no air out of vents.i have vacuum going into the hard line thru the fire wall passenger side. Looks like those hard lines go to a violet and gray soft line. . Stumbled. Any ideas what is going on? Can I cut that violet line and reroute vacuum from hard line to the other side of this plug (yellow) can’t think of what else it could be. Don’t really want to take head unit back out. Car has been sitting for 10 years