Home | Contact Us | FAQ | Search & Site Map | Link to Us
Sign In | Join | Other 45 Sites in Network
HomeAnnouncements
Discussion Groups
By Brand
BMWChevroletDodgeFordGMHondaLexusMercedes-BenzNissanPeugeotToyotaVolkswagenOther Brands
By Topic
4x4 CarsRVsDrivingMaintenance & RepairCar AudioCollectible Cars
Country Specific
Australian ForumsUK Forums
ArticlesAuto InsuranceBuyingCars & TechnologyMaintenanceMiscellaneousSafety
DMV Resources
Related Topics
MotorcyclesBoatsMore Topics ...

Car Forum / Pontiac / Pontiac Cars / February 2008

Tip: Looking for answers? Try searching our database.

2000 Pontiac Gran Prix GT Air Conditioner Problem

Thread view: 
Enable EMail Alerts  Start New Thread
Thread rating: 
Ray - 20 Feb 2008 14:26 GMT
My vehicle has a dual climate control system and the conditioned air that is
emitted from the driver's vents is substantially warmer than that
out of the passenger vents.  This condition exists when both controls are
set for the same temperature in dual mode as well as when set by the
driver's control in non-dual mode.  For instance left side air output is 72
degrees when the right side air output is 47 degrees.

The left side blend control motor and the exterior air temp sensor were both
replaced with no apparent effect.  The a/c technician working on my car said
he got a 105 code when he ran the BCM diagnostics using the climate control
system switches.  He said the 105 code indicates a bad left side blend motor
control motor and this code was present even after replacing the motor with
a new one.  He also said he was able to manually move the blend door from
the full heat to the full cool when he had the motor out and could detect no
binding during the full travel of the door.  Unfortunately, he was not able
to isolate the problem.

I suspect there is a wiring problem causing this situation but without a
wiring diagram I don't know where to start.  Any suggestions you have on
isolating this problem will be greatly appreciated.

Ray
Ray - 28 Feb 2008 18:38 GMT
Here's what I have learned in the process of trying to isolate this problem:

   1.  No OBD current codes are indicated when accessing the diagnostics
through the climate control panel.  A history code of 105 shows because I
removed and replaced the driver-side blend door motor.

   2.  With the driver-side blend door motor removed I could detect no
binding when physically moving the blend door from full-heat to full-cold
position.  However, when the blend door was physically moved to the full
cold position the temperature out of the driver-side vents was the same as
out of the passenger side in single mode operation.

   3.  Changing the driver-side temperature control from full heat to full
cold positions appears to cause the  driver-side blend door motor to move
through its full travel (that is, from the full heat index marking on the
motor to the full cold index marking).  However, the driver-side outlet
temperature is approximately 15 degrees warmer than the passenger outlet
temperature when the temp control is in the max cold position.

   4.  Replacing the driver-side blend door motor and the exterior temp
sensor did not correct the problem.

It appears to me that for some reason the driver-side blend door is not
being moved to the full cold position when the motor is installed and the
temp control is set at max cold even though the motor appears to move to the
full-close index mark.  When I drive the motor to the full-cold position and
remove it from the air box, the blend-door appears to be sitting in the full
cold position.

Is it possible the a/c & heater controller is commanding the blend-door
motor to a position just off the full cold position even though the motor
appears to be at the index mark?

Because of item 2. above, I am convinced the blend-door motor is not moving
the door to the full cold position even though the shaft position index on
the motor appears to indicate otherwise.

Is it possible to adjust the blend door shaft positionslightly so the motor
will definitely move the door to the full cold position when the temp
control is set to max cold?

Ray
David Courtney - 28 Feb 2008 18:57 GMT
Are you sure there's not something like a loose piece of insulation or
paper or something blocking part of the AC evaporator core... so the
driver's side just isn't getting all of the cold air it's supposed to?
   I had a foam "gasket" come loose in my Silverado's heat duct... and it
made it's way into the squirrel-cage blower.

> Here's what I have learned in the process of trying to isolate this
> problem:
[quoted text clipped - 39 lines]
>
> Ray
Ray - 29 Feb 2008 02:17 GMT
The reason I don't think there is anything blocking a part of the evaporator
core is that I can physically move the blend door to the full-cold air
position and get 40 degree air out of the driver-side vents.

Ray
David Courtney - 29 Feb 2008 02:37 GMT
Makes sense... I wish I knew more about how that system works.

> The reason I don't think there is anything blocking a part of the
> evaporator core is that I can physically move the blend door to the
> full-cold air position and get 40 degree air out of the driver-side vents.
>
> Ray
 
Sign In
Join
My Latest Posts
My Monitored Threads
My Blog
My Photo Gallery
My Profile
My Homepage

Start New Thread
Enable EMail Alerts
Rate this Thread



©2009 Advenet LLC   Privacy Policy - Terms of Use
This website includes both content owned or controlled by Advenet as well as content owned or controlled by third parties.