Heat/AC Blend Doors

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gmbellew

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If the diverter valve link connector is broken will it disable all blend door function? Mine is broken and air comes out the floor and will not switch to vent or defrost.
in my experience a broken diverter will still move the door for the dash/floor door and switch some, but not all, flow.
 

454-k10

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in my experience a broken diverter will still move the door for the dash/floor door and switch some, but not all, flow.
Thank you
 

jayzon

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I’m having the same issue, everything seems to be in working order, my clip isn’t broken and I’ve tried every adjustment but my blend door still doesn’t completely close or completely open. Probably lacks 1/2” from fully closing for defrost and a little more than that when switched to vent. Do u think that new clip would make any difference? Even if mine isn’t broken?
 

gmbellew

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not sure. normal operation is that a little air comes out defrost when on floor and a little air comes out the floor when on defrost. nothing should come out vent when on floor or defrost and nothing should come out floor/defrost when on vent.

but I do still get a little air out the floor when on vent that I don't spend any time worrying about. the door is a little warped and I am living with it vs trying to break it in an effort to fix it
 

jayzon

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I can live with a little bit just mine seems excessive, I can physically close it all the way by pulling the rod, but it pushes against that spring so I have no clue. Bought a new actuator just for the hell of it, just hasn’t come in yet. I’m gonna have to take it back out and double check everything, sux cause I just had it out replacing the heater core.
 

gmbellew

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there is a rod that connects two doors that work together. you may make sure that the connector isn't 180 degrees out.
 

jayzon

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Are u talking about the outside threaded rod that works in conjunction with the blender and vent door? I’ve tried every adjustment that I can, and the doors don’t bind or anything, air flows to correct places when I switch modes just doesn’t seem to have enough to close completely. It’s open enough I can get my fingers through it. And I’ve checked my vacuum lines as well. Previous owner removed all ducts and zip tied that blender door shut, so I have no idea what it was doing before. I’m trying to put AC back on it plus all of the ducts reinstalled.
 

gmbellew

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yes, that's what rod I was referring to. the connector on the blend door, if I remember right spins and can be installed 180 deg out. the length of the rod can also be adjusted when it is put on that connector. it was about the only thing i could think of to check if the clip on the door wasn't broken.
 

jayzon

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Yeah I’m right there with ya, just don’t know what else to check. Been a pain in my a** because I hate to put it all back together like it is. Guess I’ll just have to triple check everything when I get it back apart and if I can’t find anything it’ll just have to be, unfortunately
 

jayzon

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So I took it back apart this evening and saw the blend door clip lever is slotted. So there is a bit of adjustment that can be done. The screw was tight but I’m hoping it was just off from the get go. Gonna go ahead and replace the actuator anyways since I have it ordered. I’m hoping this will help, only bad thing is it’s all gotta be put back together and checked to see if I have it right.
 

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daniac

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Here's a few pictures from my '85. Your's should be similar, but I know my vacuum hoses are color coded a little different that this chart. For reference, the piece in the back ground of the 1st photo with the yellow and red boxes is supposed to lay on top of the piece in the foreground.

There are technically 5 doors/flaps that open. Three are in this picture, the other 2 are for recirculating air. The one in the yellow box is controlled by a cable attached to the top of the box (Hot/Cold slider on head unit). The one in red box is controlled by the vacuum pod in the red box. That pod is the only one that pushes and pulls with vacuum hooked to both sides of it. The last door pictured here is positioned horizontal on the bottom left of the yellow box (also photo #3 & #49 in photo #2). It controls defrost. The vacuum pod will pull this door toward the rectangular opening at the bottom center of the photo to close off the floor vent and direct air towards the windshield.

In photo #2, the vacuum pod near #53 are depicting the same pod, just 90 degrees off so you can see the movement of the defrost door.

The other 2 doors not pictured are the one at the right kick panel and the flap under the cowl (near yellow arrow in photo #4) that blocks fresh air when the kick panel door is open to recirculate air from the cab on Max mode.

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Saltshaker787

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Hello im new here ...I have a 90 suburban just put in a reman heaterbox and replaced climate module (new) im trying to figure out the diverter door that open evaporator housing is closed on max ac....but open when climate module is on off...also no air when in defrost mode... but the door to the evaporator housing is open when in defrost mode...currently how im getting cold air out of dash vents...any help would be awesome!
 

gmbellew

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Hello im new here ...I have a 90 suburban just put in a reman heaterbox and replaced climate module (new) im trying to figure out the diverter door that open evaporator housing is closed on max ac....but open when climate module is on off...also no air when in defrost mode... but the door to the evaporator housing is open when in defrost mode...currently how im getting cold air out of dash vents...any help would be awesome!

you might have the vacuum lines on the wrong ports at the hvac controls?
 

Saltshaker787

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Yeah I cant see what else since every thing is updated in the box...thanks
 

Saltshaker787

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U mean wrong vaccum lines could be on the pod....have em criscross? The vaccum harness appears to only go on one way on the back of climate control module....thanks for your help
 

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