defroster frustrations......help......

[nevada70chev]

ok, its a beautiful day in northern nevada, so i thought i'd tinker on the truck. well my defroster has been working less than adequate. i've got great flow to the middle vent and side vents (i've got a/c) but i don't have the air flow to the upper vents on the dash. what am i missing? or is something not adjusted correctly? all my control cable seem (in my little knowledge) to be working and connected. is there some sort of flap which redirects the air from the side vents to the defroster vents? my wifes says "you got a bird nest in there?" any and all help is always appreciated. thanks in advance.

[rage'nrat638]

well the hose's could have fallen off....
there's two flappers.....
one in the center that you can see......
and one on the passenger side up and behind.....

move the levers and feel if it's moving both ways....
cable may have come off the flapper door post...that it connects to
good luck mark

[Classic Heartbeat]

Sounds like your deverter box went south on you. Common problem in these trucks. You will have to pull it out and see if the flap on the inside has broken. WES www.ClassicHeartbeat.com

[lukecp]

The hoses proably have fallen up. Follow them up underneath the dash and make sure they are still connected to the vents. They fall off on my truck all the time....

[Blue Beard]

Mine was the diverter box. Wes is right on the money..............

While your at it check all the duct work while you have it out...

[jeffbo]

My truck has been the exact same way lately, and I know the ducts aren't disconnected. So how did you fix it then? Did you just get a new diverter box, or did you just make some kind of adjustment on it to fix the problem?

[rage'nrat638]

you will only need the new box if the flapper is broken.....

[nevada70chev]

....MAN..i love this board, boo coo good advice and help...all of the duct hoses are connected and got great flow out of the first stage box that the side vents, center vents are connected to, then the second stage box there is minimal flow. to the best of my knowledge the cable connected to the lever on the outside of the second stage box is moving the flap i can feel through the holes in the box, but i don't know about a second flap or where to check for it. any one got a diagram picture of what i'm suppose to look for? again thanks. keep the advice / wisdom coming, i can use it.....

[rage'nrat638]

reach under the dash on the passenger side...below the glove box.....you should be able to feel the cable and pin that the cable hook's to,,,, thats the one you want......

[nevada70chev]

...MAN....this board is great and the "boo coo" knowledge has always helped me. all my duct work is connected, there is great flow from the first box (center vent and side vents), and also to the best of my visual, all the cables are connected and moving when i change their positions. i can feel the movement of a flap in the second box from the lever connected to the outside, now where is the "second" flap in the diverter box? how do i know if it is broken or disconnected or ???. thanks again.

oh, does anyone have a diagram or picture of what i should look for??? thanks.

[rage'nrat638]

stick your hand on the flapper cable and move the 2nd lever to defrost and back you should be able to feel it moving and hear it
if not...it's broke at the a/c controller on the dash......

if you feel it moving down below but don't hear the flapper ....
it broke

[Longhorn Man]

For those who are suffering from the winter cold and need to get there defroster working pronto...find the hose that is getting the air, and reroute the hoses so the air is blowing on the glass instead.
Kinda bakyard-ish...but so is a towl as a defroster.

[nevada70chev]

well, is there a simple way to fix the problem? or do you just replace it?

[JimKshortstep4x4]

There is away to repair the door in the diverter box. We have riveted tin straps to the plastic door and then welded the straps to the actuater rod. The repair works, but I think replacement of the diverter box is the way to go.

Jim

[Blue Beard]

Replacing the box will give you a lot of trouble free years.........

Quick fixes I've learned are just that........

[67chevemall]

Those two flabber hoses are the biggest pain in the a55!
I must have two rolls of duct tape on em!

[mrein3]

Originally posted by JimKshortstep4x4
There is away to repair the door in the diverter box. We have riveted tin straps to the plastic door and then welded the straps to the actuater rod. The repair works, but I think replacement of the diverter box is the way to go.

Jim

That is EXACTLY what I did with mine. I pop-riveted a piece of tin to the plastic flap then welded that to the rod. It is BETTER than what GM did. I have to believe that if you replace it with a new one it would just be a matter of time before it too breaks.