Defrost - Help please - The 1947 - Present Chevrolet & GMC Truck Message Board Network

dubya · 03-11-2006, 01:24 PM

Hello again :-) I think I owe this board for the information that I've been able to get from it, but I haven't contributed squat...

So to take another mile:

My heater won't switch into the de-ice mode. It blows 100% out of the dash ports. Any ideas? I went through and checked for non-moving cables, and vaccuum lines, but to no avail. Where should I focus my attention.

I have a '72 k20 with AC. Thx.
W

Solver · 03-11-2006, 01:29 PM

Sounds like the flapper vent in the lower heater box has busted it's rivets and wont move even though the cable does

dubya · 03-11-2006, 01:47 PM

Thanks!!

Is that the flapper to the cable I see moving when I slide it into defrost? The tubes look good too. Dang.

W

cdowns · 03-11-2006, 02:07 PM

yeah the flapper is inside the black plastic box in the middle of the floor

davidh · 03-11-2006, 04:37 PM

It's already friggin 100F degrees here in Laredo!!!!!

pound41 · 03-11-2006, 04:55 PM

It's probably the flapper in the box like everyone else has said. I bought a new one and it works great.

03-11-2006, 01:24 PM	#1
dubya Registered User Join Date: Nov 2005 Location: Sacramento Posts: 22	Defrost - Help please Hello again :-) I think I owe this board for the information that I've been able to get from it, but I haven't contributed squat... So to take another mile: My heater won't switch into the de-ice mode. It blows 100% out of the dash ports. Any ideas? I went through and checked for non-moving cables, and vaccuum lines, but to no avail. Where should I focus my attention. I have a '72 k20 with AC. Thx. W

03-11-2006, 01:29 PM	#2
Solver Registered User Join Date: May 2000 Location: Storm Lake, Ia Posts: 1,449	Re: Defrost - Help please Sounds like the flapper vent in the lower heater box has busted it's rivets and wont move even though the cable does __________________ 1972 Cheyenne Super 20 LWB-Blue 1972 Cheyenne Super 10 LWB-Black 1972 Cheyenne Super 10 LWB-Red 1972 Cheyenne Super 10 LWB-green 1972 GMC 4x4 LWB-White 1971 Cheyenne 10 LWB-Ochre 1971 Cheyenne 20 Longhorn-Copper 1971 Cheyenne 20 Longhorn-Black 1969 Custom 10 LWB-lt blue 1968 GMC 3/4 ton-green 1968 1/2 ton swb stepside-silver 1967 Chevrolet CST 10 LWB-green 1967 Chevrolet custom 20 LWB-Maroon

03-11-2006, 01:47 PM	#3
dubya Registered User Join Date: Nov 2005 Location: Sacramento Posts: 22	Re: Defrost - Help please Thanks!! Is that the flapper to the cable I see moving when I slide it into defrost? The tubes look good too. Dang. W

03-11-2006, 02:07 PM	#4
cdowns Senior Member Join Date: Jan 2003 Location: daytonabeach Posts: 22,956	Re: Defrost - Help please yeah the flapper is inside the black plastic box in the middle of the floor __________________ 71c-10 350/2004r/4:11 lowered3/4 longbed/dead by hurricane MEANING OF DEATH::::: SOMEBODY ELSE GETS YOUR STUFF DONT BELIEVE EVERYTHING YOU THINK TAKE MY ADVISE;I DON'T USE IT ANYWAY

03-11-2006, 04:37 PM	#5
davidh Senior Member Join Date: Feb 2004 Location: Ponca city now kingfisher Oklahoma Posts: 1,220	Re: Defrost - Help please It's already friggin 100F degrees here in Laredo!!!!!

03-11-2006, 04:55 PM	#6
pound41 Registered User Join Date: Dec 2002 Location: Northern Virginia Posts: 1,268	Re: Defrost - Help please It's probably the flapper in the box like everyone else has said. I bought a new one and it works great.



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