1981 c3
Thread Starter
5th Gear
Joined: Oct 2017
Posts: 5
Likes: 0
1981 c3
Hey Guys,
I have a 1981 fully restored matching number car with 53,000 miles. My A/C only blows through the floor. defrost does not work as well. any tips? Ive read every post here and am having trouble locating the vacuum hoses. and pictures of the actual hose i need to check? thanks!
I have a 1981 fully restored matching number car with 53,000 miles. My A/C only blows through the floor. defrost does not work as well. any tips? Ive read every post here and am having trouble locating the vacuum hoses. and pictures of the actual hose i need to check? thanks!
Race Director
Joined: Jan 2001
Posts: 16,221
Likes: 118
From: Matthews NC
I can't answer your question, but I do want to say that is one nice looking '81!! And a 4-speed too! And who can't like red... 
Welcome to the forum!
Welcome to the forum!
Last edited by RMVette; Oct 20, 2017 at 07:40 AM.
Racer
Joined: Jun 2013
Posts: 311
Likes: 37
From: Sparta NC
Great looking car! If the car is well restored and hasn't been monkeyed with, I am more inclined to think the problem may be with the HVAC control if it is not switching when you move the control. Even though the car is in great shape, the plastic can become brittle with age.
Le Mans Master
Joined: Aug 2010
Posts: 5,339
Likes: 546
From: Central Texas
The vacuum switch frequently goes out on these cars. If you take the right side panel off of the transmission hump you can hear if it's leaking.
Also could be your vacuum supply hose going to the control head (vacuum switch). The hose comes out of the firewall to supply vacuum to the switch from the engine. It is frequently cracked where it comes out of the firewall. Thus no vacuum to the switch.
https://willcoxcorvette.com/corvette...-switch-77-178
Also could be your vacuum supply hose going to the control head (vacuum switch). The hose comes out of the firewall to supply vacuum to the switch from the engine. It is frequently cracked where it comes out of the firewall. Thus no vacuum to the switch.
https://willcoxcorvette.com/corvette...-switch-77-178
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Instructor
Joined: Jan 2017
Posts: 107
Likes: 12
From: New York
Had the same issue. Turned out to be the heater/ac vacuum valve. Cheap plastic piece that broke and doesn't allow the vent doors to open and close, moving the air from floor to bi to defroster. Did it many years ago and can't remember if thats the reason I had the dash out.