Bulletin No.: PI0648A
Date: Dec-2012

Subject:

Revised HVAC Blower Motor Installation Instructions

Models:

2007-2010 Cadillac Escalade Models
2007-2010 Chevrolet Avalanche, Silverado, Suburban, Tahoe
2007-2010 GMC Sierra, Yukon Models
Equipped with C42, C67*, CJ2 or CJ3 HVAC System
*Excludes all Silverado and Sierra Extended Cab and Crew Cab models equipped with C67 (these
models are built with a different HVAC module design; this bulletin does not apply)

This PI is being revised to update the Models section to add RPO information. Please discard PI0648.

Condition/Concern
The HVAC blower motor assembly, for the full size trucks listed above, has been revised. It requires modifications in order to function properly for the
model year vehicles listed above. The original style blower motor assembly is no longer available as a service part.

The design of the HVAC blower motor for these vehicles has been revised. The first design blower motor assembly has an integral cooling duct
molded into the assembly (1). The second design blower motor assembly has a cooling port and uses a separate air duct that draws cooling air from
the lower section of the HVAC housing assembly (2).

Recommendation/Instructions
Important: DO NOT replace the lower HVAC case to correct this condition.
Use the following steps to install the second design blower motor assembly and cooling duct on vehicles manufactured with the first design blower
motors.
1.

Remove the HVAC blower motor assembly. Refer to Blower Motor Replacement in SI.

2.

Install the new, second design blower motor to the HVAC module case. Refer to Blower Motor Replacement in SI. Do not connect the
electrical connector to the motor.

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3.

Place the new blower motor duct into position against the blower motor and HVAC case lower half as shown. Ensure it is in the installed
position.

4.

While holding the duct in position, use a paint pen to mark the heater case as shown, outlining the cooling duct.
Important: Do Not round-out the drilled hole. The piece of hose to be inserted into the drilled hole needs to have a tight fit. It is
recommended that a trial hole be drilled in a scrap piece of similar material to ensure the section of hose has a tight fit.

5.

Remove the cooling duct and mark the case lower for the drill location as follows:

•
•

Mark the case 13 mm (½ inch) above the edge of the case where it slopes down.
Mark the case halfway between the front and rear edges of the duct outline.

Important: To avoid damage to internal HVAC case components, do not use a standard type drill bit.

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6.

Using a single flute stepped drill bit, drill a 9/16-inch hole in the HVAC case lower half at the marked location. Do Not round-out the drilled
hole.

7.

Cut a piece of 3/8 inch ID fuel hose to 25 mm (1 inch) in length.

Ensure the hose does not become blocked by bottoming out squarely against the duct. Ensure it is positioned as shown. The duct is shown
off of the vehicle with the foam seal removed to illustrate the correct hose position. This is not the installed position.

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8.

Check the cut hose against the duct to ensure the hose in oriented correctly when installed. Orientate the hose to the duct to provide the
most airflow as shown.

9.

Install the hose into the drilled hole. Ensure the hose is retained firmly in the hole.

10. Check the installed length of the hose. Place the duct fully into position to ensure it seats fully to both the blower motor and the case lower.
11. If the duct does not seat fully, adjust the installed depth of the hose just enough to allow full installation.
12. Install the cooling duct and secure with two bolts.
13. Connect the electrical connector to the blower motor. Verify the operation of the blower motor.
14. Complete the replacement procedure. Refer to Blower Motor Replacement in SI.

Parts Information
Part Number

Description

Qty

22741027

Blower Motor Asm (Second
Design)

1

20883403

HVAC Blower Motor Cooling Duct
(for Second Dsgn. Motor)

1

11609829

Bolt/Screw

2

NPN

3/8 inch Fuel Hose

As
Req.

Warranty Information
For vehicles repaired under warranty, use:

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Labor
Operation

Description

Labor Time

D9783*

Revise/Install HVAC Blower
Motor

0.6 hr

*This is a unique labor operation for bulletin use only. It will
not be published in the Labor Time Guide.
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions
that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the
equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin
applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the
information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION

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