Need help with 79 defroster duct
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Joined: Nov 1999
Posts: 70
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From: Aston, Pa Pa
Need help with 79 defroster duct
Can anyone confirm for me that the defroster duct dose screw into the dash support and rest on the distrubution duct?. I have the factory shop manual , build sheets ect., the build sheet shows that is the case but if I were to screw the duct to the dash support it is about 3/4 inch to short, hanging above the distrubution duct. Am I missing a foam collar were it comes off of the distrubution duct or an intermediate peice not shown in manuals? Also, dose the duct just butt up to the underside of the dash outlet grille? Out of all my pictures I never took one of the duct and now it is holding me up. Any help is appreciated! :D
Racer
Joined: Aug 2001
Posts: 388
Likes: 1
From: Bridgeport CT
Re: Need help with 79 defroster duct (Dale79)
Sir:
According to ex-GM Corvette and Chrysler plant executive John H. aka John Z., that gap is intentional. If the defroster duct was “hard mounted” to the dash firewall heater or AC distributor assembly - the blower motor vibrations could be transferred to the dash instruments and thus be an annoyance. All C3 and C2 have the gap, AC or not. C1 has a cloth flex hose connection.
Happy Holidays http://www.jingandmike.com/pages/xmas.html
Geoffrey Coenen
NCRS #2473
NCM Lifetime #105
Precision Valley Corvette Museum Charter Member #20 (I think)
Vettehead #18-1
Retired #1 56, 63, 67, 68, 68, 69, 75, 99 and I want more!
(Ex-Corvette non-Executive)
According to ex-GM Corvette and Chrysler plant executive John H. aka John Z., that gap is intentional. If the defroster duct was “hard mounted” to the dash firewall heater or AC distributor assembly - the blower motor vibrations could be transferred to the dash instruments and thus be an annoyance. All C3 and C2 have the gap, AC or not. C1 has a cloth flex hose connection.
Happy Holidays http://www.jingandmike.com/pages/xmas.html
Geoffrey Coenen
NCRS #2473
NCM Lifetime #105
Precision Valley Corvette Museum Charter Member #20 (I think)
Vettehead #18-1
Retired #1 56, 63, 67, 68, 68, 69, 75, 99 and I want more!
(Ex-Corvette non-Executive)
Le Mans Master
Joined: Sep 2002
Posts: 5,236
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From: Myrtle Beach SC
Re: Need help with 79 defroster duct (Dale79)
Ijust went through this exercise on my 78 which is identical to your 79. The duct (defroster duct) screws into the dash pad and aligns itself with the distributor duct that transfers heated air from heater core to the defroster duct. I was surprised to see a gap...but didn't modify it because how often do you use the defroster? Or, should I say...I seldom use the defroster. Now, I may not have understood your question regarding the defroster duct screwing into the dash support...you mean dash pad? Or do you mean the windshield brace (metal bracket that runs length of the dash but attaches the dash pad. Defroster duct attaches to the pad. I believe the bracket is more inland.
There is no foam collar and yes...it butts up to the grille. I attached the duct that got topside to see if it was aligned before snugging it up. I learned the hard way...had it snug and than realized it was not aligned on top. I'll check my pics but don't believe I have anything to help.
There is no foam collar and yes...it butts up to the grille. I attached the duct that got topside to see if it was aligned before snugging it up. I learned the hard way...had it snug and than realized it was not aligned on top. I'll check my pics but don't believe I have anything to help.
