A/C BLOWER MOTOR NOISE INSTALL NEW BLOWER MOTOR COVER

SUBJECT: A/C BLOWER MOTOR NOISE/WHINE

MODELS: 1988-1990 C/K LIGHT DUTY TRUCKS WITH AIR CONDITIONING (RPO C60)

GMC TRUCK RECOMMENDS THAT A COPY OF THIS BULLETIN ALSO BE FILED UNDER SECTION IB - AIR CONDITIONING

Some 1988-90 C/K trucks may experience a whine or noise from the blower motor. To correct this condition, a blower motor cover has been released to insulate the noise. Before installing this cover, however, be sure to check the blower motor and fan for proper operation. Compare the complaint noise to a non-complaint vehicle to determine if the noise is in the "normal" range, or if the motor or fan should be replaced. In addition, the cover will not mask the noise of the fan rubbing on the "squirrel cage", thus this must be corrected separately.

SERVICE PROCEDURE (Figure 1):

1. Prepare the truck; disconnect the battery cable.

2. Remove the glove box insert.

3. Remove the right lower dash bolt and kick panel for access to the blower motor case.

4. Remove the courtesy lamp.

5. Disconnect the connector from the ECM, and remove the ECM through the glove box.

6. Remove the four screws on the ECM mounting bracket, and remove the ECM mounting bracket

7. Disconnect the electrical connection at the blower motor.

8. Install the blower motor cover.

9. Connect the electrical connection at the blower motor.

10. Install the ECM mounting bracket on the blow-motor case.

11. Install the ECM and the electrical connection to the ECM.

12. Install the right lower dash bolt and kick panel.

13. Install the courtesy lamp.

14. Install the glove box insert and reconnect the battery.

SERVICE PARTS INFORMATION

Part Number Description Quantity ------ ------------ -------- 52457225 Blower Motor Cover 1

Part are currently available from GMSPO.

WARRANTY INFORMATION

For vehicles repaired under warranty use:

Labor Operation: T7166

Labor Time: 0.5 hr.

NOTE: Labor Operation is coded to base vehicle coverage in the warranty system.

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those 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 a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.