Auto Parts: 1994 Chevy c1500 pickup air, chevy c1500, pep boys

Question
When I turn on the key a snapping noise starts below the blower motot and
the diverting flap for max/outside selection jumps with each snap. After a
minute or more it stops and everything works fine. When I turn off the vehicle
it does it again. The after a minute or more it stops. I have tried to find if it is
vacuum activated but could not find any thing that looks like a vacuum
connection.
  How do I get to the mechanism to find out why it's slipping? I don't see any
bolts that connect the blower to the firewall, only to the distribution assembly
for the dash outlets.
 Thanks,
 Mick

Answer
Hi Mick,

Sounds like the blend-door actuator is bad. The blend door opens when you start the vehicle and closes when the vehicle is turned off. It allows fresh air to be circulated through the vehicle any time it is running.

I'm not exactly sure how you access the actuator motor but I do know the entire dash assembly needs to be removed to access the fasteners attaching the blend-box which houses the door as well as the actuator.

Looking for a reputable service technician? My advice on finding a good technician is: Steer clear of the dealership and 'chain' stores like Firestone, Sears, Pep Boys, Monro Muffler/Brake, Midas, etc. as they usually only employ ONE ASE Certified Tech just so they can say they do and chances are, that guy is the asst. manager or manager and is not in the store to diagnose/repair vehicles anyway. Find a service location in the link below or get some names out of the yellow-pages and do a drive-by. Garages that employ ASE Certified Technicians will be marked with the 'Blue-Seal' insignia. If unsure about whether a place employs Certified Techs, just ask to see their credentials. ALL ASE Certified Technicians will be PROUD to show and display their certificate(s).

Thanks for the question, I hope this information was helpful to you.
Fred
Knucklebusters Used Auto & Truck Parts, Inc.
www.knucklebusters.us
570-453-0910
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Looking for an ASE Certified shop near you? ASE Certified Technicians are the BEST of the BEST!
Click here: http://www.ase.com/bluesealsearch/locator.php