No air from defrost setting
10-17-2007, 07:33 AM
#1
Pro
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No air from defrost setting
Hi again, up here its beginning to get cold again. Took the car out for a drive and turned the heat on and the setting to defrost and I was getting no air from the top dash on the defrost setting. All the warm air was blowing at my feet. I changed the setting to vent and nothing was coming out the vent either, but still blowing hot at my feet. I haven’t used the defrost setting since last fall and noticed that last fall it took a while before the defrost setting kicked in, now it’s not working at all. I checked the shop manual and noticed that there is a vacuum valve somewhere along the center kick panel. It mentions that this is the defrost valve and has a vacuum line with a blue stripe on it. How would I trouble shoot this. Should I hook up my vacuum pump to the vacuum valve and see if it closes or opens?
Thanks
Thanks
10-17-2007, 07:43 AM
#2
Burning Brakes
Member Since: Dec 2005
Location: west babylon new york
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check under hood and see if you can find a broken vacumn line ,it comes in on the right side of dist you didn;t say what year but most come into car in this area ,also if car is running you may here a hissing noise
10-17-2007, 08:00 AM
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My mistake it's for my 1980 corvette, I know that last year when I set it to defrost you would hear a hissing sound and the defrost would kick in. When I selected the defrost this time, I did not hear any hissing sound and the warm air was just coming out at my feet.
10-17-2007, 08:03 AM
#4
Drifting
Member Since: Dec 2004
Location: Edgewater (20 miles south of Daytona) Florida
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Isn't there a 'Y' block with a flapper valve to divert air just under the defroster opening of the dash? If you can reach that, flip the valve to the opposite side. I thought there was a cable attachment to it on my '66, but it's been way too many years gone in my car to be sure. Glenn
10-17-2007, 08:10 AM
#5
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I checked both the shop manual and the Assembley manual and there appears to be a seperate vacuum diverter for this function. I am wondering or should check first to determine if the vacuum diverter is getting any vacuum at all. I noticed in the manual that the diverter has a rod that engages some other assembly, I guess this is to actuate the defrost to work. I havent checked anything out yet, hoping to try this weekend.
