Problem with HVAC on '87.

[Snorman]

The other night I noticed that although the AC and heat work, all of the air is coming out through the vents for the defroster and not the vents on the front of the dash board. No matter what position I place the selector on the climate control in, it doesn't change.
In anybody's experience is this usually a bad climate control unit? Any other suggestions on where to start to troubleshoot?
S.

 

[Turbo Brian]

The default position for the heat/air conditioning vents is the defrost position. In other words, if no vacuum is present, that is the position that the doors fall to. Check for a vacuum hose off somewhere, usually in the engine compartment.

 

[Snorman]

That's what I was thinking.
Is there a line off the vacuum block for the vent control?
Thanks.

S.

 

[Boost231]

hey

look under the dash at all the different color hosees and make sure they are all pluged in. once u find the hose that is off i bet the vents will work normal

brent

 

[salvageV6]

Purple hose is the feed to the vent assembly.

 

[Snorman]

Fixed it!
This evening, I went for a quick spin and noticed that my cruise wasn't working. The light worked, but it wouldn't hold speed.
At this point, I knew it had to be a common vacuum line problem.
I backtracked the vacuum line from the cruise control assembly by the chacoal canister, then remembered replacing some vacuum hoses along the driver's side fuel rail. When I did this, I put the check valve in from of the EGR on backwards. In 30 seconds, I flipped it around and all is good again!
Thanks for the help.
S.