Need help with Ac vacuum


TurboBuick.Com Supporter!
Jun 23, 2013
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 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
I have vacuum on the hard line that goes under blower motor. Which I guess goes to the violet line
There are 2 hardliners that run inside to the hvac control. 1 is vacuum signal, the other goes to heater valve. Double check and make sure they are not crossed.
Ok the one that has vacuum goes inside the cab the other hard line coming from the cab goes to the heater valve. This is correct on my car. Let me ask you a question if I turn the heat on and slide temperature to hot, should I get vacuum on the hard line going to heater control valve? This would tell me things are working correct. Is this thinking right? What about the valve behind the glove box where the violet line should come under by each? What pulls that open?
Thanks by the way. This car was stolen about 10 years ago. Had to rebuild it . Motor blown and interior stolen. Been in my garage and shipped across country getting it right. This site is a awesome resource and has a great people . Thanks in advance from someone who appreciates people who help us out.
Update I found the problem. I disconnect the vacuum plug behind glove box to check for vacuum. Checked out, I had on the violet line pushed it back together then zip tied it tight and the vents switched . Everything is working. Thanks to everyone .