A/C controls

[gric_az]

Sup guys. On my 88 , the ac selections are either blow thru the dash or floor vents. Can't select at same time, the arrows roll completely in either direction. Do yours do the same?

 

[AK49BWL]

They don't stop if you press the same key again? Say it's on face vent, you press the floor vent on the left under face vent, the arrows start moving down, press the floor vent button again and it's supposed to stop at that point. Same with the defrost/floor button.

 

[DerekTheGreat]

What AK said. They're a little tricky to get used to, I remember when I got my first GMT400 I thought the same thing. Then I figured out if you tap the button again it'll stop where it was, so long as you see the little arrow indicators moving.

 

[gric_az]

They must not be working correctly then. I think one of the blend motors is faulty. Cause I get some air out the floor vent when it's on the dash only. I've tried pushing it after the arrows start moving, pushing the middle of the button, no dice. I've replaced the motor behind the radio and by the gas pedal but it still does the same thing. Haven't changed the one behind the glove box.

 

[Dropped88]

One by gas pedal is mode
One behind radio is temp
One behind glove box is recirc.

So that one wont be your problem. You need to see if you can see actuator move by gas pedal when you try moving to defrost, vent, etc

 

[gric_az]

The one by the pedal might be bad. It works in all positions, defrost, dash, and floor vents. Just that in dash mode it still let's air pass to the floor.

 

[AK49BWL]

That COULD be a broken blend door itself. That age, plastic is brittle AF... And the rubber foam stripping in there probably ISN'T in there anymore due to deteriorating.

 

[east302]

Not sure if the 88 is setup like my 98, but the damper at the floor has rubber trim that eventually breaks off and causes air leak to the floor.

Pull panel at transmission hump (one screw and pivot down)...

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Red arrow points to torn flexible seal at edge of damper...

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New damper...

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[gric_az]

I'll give that a shot. Thanks for the info!