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