heat only blowing from defrost vents
Thread Starter
Junior Member
Joined: Sep 2008
Posts: 20
Likes: 0
From: murfreesboro tn
Car: 1984 camaro
Engine: 355 sbc mildly built
Transmission: th350 w/shift kit and megashifter
Axle/Gears: 272 posi borg warner
heat only blowing from defrost vents
hey guys i have a 84 z28 and i just dropped in a 350. when i turn the heater on it only blows from defrost. i've learned it switches off vacuum. which vacuum hose do i need to hook up and to wear? thanks
Joined: Jul 1999
Posts: 503
Likes: 0
From: New York City
Car: 1986 IROC
Engine: 355 Tpi
Transmission: 700r4
Axle/Gears: 9 Bolt 3.27
Re: heat only blowing from defrost vents
There should be a hard plastic vacuum line on the firewall near the HVAC box. hook it to manifold vacuum, that should do it.
Thread Starter
Junior Member
Joined: Sep 2008
Posts: 20
Likes: 0
From: murfreesboro tn
Car: 1984 camaro
Engine: 355 sbc mildly built
Transmission: th350 w/shift kit and megashifter
Axle/Gears: 272 posi borg warner
Re: heat only blowing from defrost vents
thanks i just went out and tried that one. it works great now. thanks
Junior Member
Joined: Apr 2009
Posts: 19
Likes: 0
Re: heat only blowing from defrost vents
sorry to bring this topic back up. I am having this same problem, are you talking about where the big thick set of wires comes through the firewall and there are 2 really small hard plastic lines coming in? One goes to the bypass(which I removed) and one goes to the back of the throttle body? I need help, only my defrost works. Also the cruise doesn't work, could these be connected?
Thread
Thread Starter
Forum
Replies
Last Post
