AC Panel vents - no air?!

[Arc Angel]

Hello SHO Guru's...I've got a small glitch with an otherwise perfect SHO. My panel vents produce no air, whether in "Auto" or otherwise. Air blows out the heater ducts, the defroster ducts, but nothing at all out of the front panel (vent) ducts. Any clues as to what I can do or look for to try and correct this minor little problem? Thanks in advance for any reply.

Frank

 

[projectSHO89]

Welcome!

Year?? Manual or Auto A/C??

There is a vacuum motor on the A/C plenum that directs airflow to the panel vents. It is likely that this motor (or the door), its linkage, or its vacuum supply is the problem.

Don't have my service documentation immediately available so I can't give you the exact location of the motor.

Steve

 

[NiNeTy Fo SHO]

Did you open the vents??? (They can be closed....Im an a**, I know.)

Welcome to the SHO world.

 

[Redline]

I had a similar problem on mine (air only from defrost). It turned out to be the vacuum line. If you look by the firewall, right behind the engine, you will see where the small black vacuum line goes through the firewall right by the heater core hoses. Anyway, where it comes through the firewall and makes a bend right there mine had a hole and actually broke in half when I touched it. Might wanna check it out anyway.

 

[Arc Angel]

Thanks. I'll check that firewall vacuum line connection out right now. By the way...it's a 92 SHO, 306,572 original miles, with every single service documentation and record since day one. Just picked it up off the original owner (from Woodstock, New York) who almost cried when I left with it. I hope it has the same effect on me during the time I have it. Runs fantastic. Mechanically (short of this little glitch with the air from the vents) perfect. Midnight blue, but could use a new paint job on the hood and trunk and top, as it's faded from sitting outside (sunlight and weather effects). Viper alarm, Passport ****** hardwired radar detector, Eibach Springs with Tokiko Struts, Borla Stainless Steel Exhaust...the gentleman REALLY cared for this car well.
Sorry for the rant...I'm getting into this SHO thing.

Frank Germano

 

[projectSHO89]

It's not the vacuum supply line from under the hood. n You don't have the correct symptoms to match that problem.

Focus on the relevent motor and its associated components.

Steve

 

[Arc Angel]

Okay, I checked that vacuum line and it was fine - inside the passenger compartment and inside the engine bay, as well. From the last reply, I guess there's an electronic component to check. Would someone be so kind as to point out WHERE and WHAT that item might be? I'm flying blind without a service manual on this one. I'm an aerospace engineer, and you can get as technical as you like with the help; simpler is always better, though.
Again - the system is fully functional, air conditioning and heater and temperature wise. The only glitch is that no matter what the dash switch settings are, no air will blow out of the panel VENTS. Quite annoying, actually, especially on hot 90 degree plus days! If someone can zero me in on what to tear into or look for, it will be greatly appreciated.
Thanks,

Frank

 

[projectSHO89]

Just moved so all my books are in boxes .... somewhere.

Unfortunately, my desktop computer puked its power supply so I don't have access to my service cds....

Bah!

Perhaps someone will look in the Heating and Cooling section of their documentation and find the relevent vacuum motor.

Manual or Automatic climate control?

Steve