A/C - Whistle Noise From Cowl Vent Area
BULLETIN NUMBER: 93-1B-70SECTION: 1B A/C
NUMBER: 10
CORPORATE REFERENCE NUMBER: 361203
DATE: May 1993
SUBJECT:
WHISTLE NOISE FROM RIGHT COWL VENT AREA (REPLACE VENT ACTUATOR)
MODELS:
1992-93 S/T TRUCKS WITH AIR CONDITIONING
CONDITION
Some owners of 1992 and 1993 S/T Trucks equipped with air conditioning may experience a whistling noise from the right cowl vent area when the air conditioning controls are in the BI-LEVEL mode or when switching from the MAX to NORMAL modes.
CAUSE
The whistle noise is caused by air being forced past the vent seal.
CORRECTION
To correct this condition a revised vent door actuator with a stronger spring applying additional force to the vent door has been released. The revised actuator was released in production beginning with the following VIN'S:
MORAINE 1GKDT13W4P2515620
PONTIAC WEST 1GTCS19Z4PO510568
SHREVEPORT 1GTCS14R0P8510883
SERVICE PROCEDURE
Follow "Plenum Side Vent Actuator Replacement" procedure outlined in section 1B of the 1993 S/T Service Manual.
SERVICE PARTS INFORMATION
Part Number Description Qty
1996833 1 Actuator, Inside Air Valve 1
Parts are expected to be available on 4/12/93.
WARRANTY INFORMATION
For vehicles repaired under warranty use:
Labor
Description Labor Time
Operation
D1790 Actuator, Vacuum Use applicable
Diaphragm, Replace Labor Time Guide