INSUFFICIENT HEAT TO DRIVER'S SIDE & COLD AIR FROM LEFT

REVISION: 09/05/97

THIS BULLETIN IS BEING REVISED TO CORRECT THE VIN BREAKPOINTS, REVISE THE SERVICE PROCEDURE AND CHANGE FIGURE 2. PLEASE DISCARD CORPORATE BULLETIN 66-11-04 (GROUP REFERENCE 1 - HVAC). ______________________________________________________________________

SUBJECT: INSUFFICIENT HEAT TO DRIVER'S SIDE AND COLD AIR FROM LEFT KICK PANEL AREA (INSTALL AND MODIFY DUCTS AND SEAL BODY OPENINGS)

MODELS: 1996-97 CHEVROLET M/L MODELS - BUILT PRIOR TO VIN BREAKPOINT - VB110256 1996-97 GMC M/L MODELS - BUILT PRIOR TO VIN BREAKPOINT - VB503618

CONDITION:

AN OWNER MAY COMMENT THAT INSUFFICIENT HEAT IS REACHING THE DRIVER'S AREA FROM THE HEATER DUCT AND THAT A DRAFT OF COLD AIR CAN BE FELT COMING FROM THE LEFT KICK PANEL.

CORRECTION:

INSTALL SEALS BEHIND THE LEFT KICK PANEL TO BLOCK THE FLOW OF COLD OUTSIDE AIR AROUND THIS AREA AND INSTALL ADDITIONAL DUCTS AND MODIFY AN EXISTING DUCT TO INCREASE WARM AIR FLOW TO THE DRIVER'S SIDE FROM THE HEATER DUCT.

SERVICE PROCEDURE:

COLD AIR INTRUSION

1. REMOVE THE LEFT FRONT DOOR STEP TRIM PLATE.

2. REMOVE THE LEFT COWL AND TRIM PANELS.

3. PULL BACK CARPET AS REQUIRED TO GAIN ACCESS TO OPEN AREA (FIGURE 1).

4. INSTALL PATCH, P/N 15027978, OVER THE LOWER ACCESS SLOT IN THE PLENUM (FIGURE 1, #2).

5. APPLY THUMB GRADE STRIP-CAULK, 3M PART # 08578 OR EQUIVALENT, OVER THE LOWER OPEN GAP FACING REARWARD INSIDE THE UPPER ACCESS SLOT (FIGURE 1, #1).

6. RETURN THE CARPET TO THE ORIGINAL POSITION.

7. REINSTALL TRIM PANELS AND PLATE.

ADD REDUCER TO SIDE WINDOW DEFOGGER DUCT:

1. REMOVE THE I/P EXTENSION FOLLOWING THE PROCEDURE IN SECTION 8C OF THE SERVICE MANUAL.

2. REMOVE THE ENGINE COVER FOLLOWING THE PROCEDURE IN SECTION 10A4 OF THE SERVICE MANUAL.

3. LOCATE THE SIDE WINDOW DEFOGGER FLEXIBLE HOSE AND REMOVE IT FROM THE HEATER CASE (SEE FIGURE 2).

4. INSTALL THE REDUCER, P/N 15740469, ONTO THE FLEXIBLE HOSE (FIGURE 2).

5. REINSTALL THE SIDE WINDOW DEFOGGER FLEXIBLE HOSE TO THE HEATER CASE.

6. REINSTALL THE ENGINE COVER.

7. REINSTALL THE I/P EXTENSION.

ADD EXTENSION TO THE HEAT DUCT:

1. LOCATE THE HEAT OUTLET DUCT ON THE DRIVER'S SIDE (FIGURE 3, A).

2. USE A SUITABLE TOOL TO CUT OUT THE PLASTIC CENTER "V" PORTION OF THE DUCT OUTLET AS SHOWN IN FIGURE 4, #1.

3. TO INSTALL THE DUCT EXTENSION OVER THE DUCT, THE RIGHT SIDE SHOULDER PORTION OF THE DUCT MUST BE REMOVED AS SHOWN IN FIGURE 4, #2. FACING FORWARD, MEASURE 2.5 INCHES FROM THE LEFT AND MARK THE DUCT. USING THIS MARK AS A GUIDE, TRIM OFF THE RIGHT SHOULDER OF THE DUCT BY CUTTING UPWARD 1.25 INCHES FROM THE END OF THE DUCT, AGAIN REFERRING TO FIGURE 4.

4. WITH THE SHOULDER PORTION OF THE DUCT REMOVED, DRILL A 9/32 INCH HOLE IN THE LEFT SIDE OF THE DUCT, 1.25 INCHES UP FROM THE BOTTOM OF THE DUCT (FIGURE 4). THE REMOVED PORTION OF THE DUCT OPENING ALLOWS THE DRILL TO BE POSITIONED SO THE HOLE CAN BE MADE GOING THROUGH THE DUCT FROM RIGHT TO LEFT.

5. DRILL A CORRESPONDING 9/32 INCH (OR SLIGHTLY LARGER) HOLE IN THE EXTENSION (P/N 15021727) ON THE LEFT SIDE, 1.25 INCHES FROM THE TOP (FIGURE 3, A).

IMPORTANT: THE MOLDED PART NUMBER ON THE DUCT EXTENSION MUST FACE THE FRONT OF THE VEHICLE (FIGURE 3, A). DRILL THE HOLE IN THE DUCT EXTENSION ON THE LEFT HAND SIDE WITH THE PART NUMBER FACING TOWARD THE FRONT OF THE VEHICLE.

6. INSTALL THE EXTENSION OVER THE EXISTING DUCT AND SECURE WITH THE PUSH IN FASTENER.

PARTS INFORMATION:

P/N DESCRIPTION QTY 15152423 DUCT SERVICE KIT 1 (KIT CONTAINS ALL P/N'S LISTED IN SERVICE PROCEDURE)

PARTS ARE CURRENTLY AVAILABLE FROM GMSPO.

WARRANTY INFORMATION:

FOR VEHICLES REPAIRED UNDER WARRANTY, USE:

LABOR OP DESCRIPTION LABOR TIME D1410 MODIFY AND INSTALL HEATER DUCT .5 HR & SEAL BEHIND LEFT KICK PANEL PLUS .5 OTHER HR

IMPORTANT: LABOR OPERATION IS CODED TO BASE VEHICLE COVERAGE IN THE WARRANTY SYSTEM.

FIGURES: 5

CAPTIONS:

FIGURE 1 1. CAULK LOCATION COVERING OPEN GAP 2. PATCH LOCATION OVER LOWER ACCESS SLOT

FIGURE 2 1. SIDE WINDOW DEFOGGER DUCT REDUCER

FIGURE 3 1. MAIN HEATING DUCT CENTER "V" PORTION 2. MAIN HEAT DUCT RIGHT SHOULDER 3. MOLDED PART NUMBER LOCATION

FIGURE 4 1. REMOVE MAIN HEAT DUCT CENTER "V" PORTION 2. REMOVE MAIN HEAT DUCT RIGHT SHOULDER 3. DRILL HOLE FROM THIS SIDE

FIGURE 5 1. VIEW OF COMPLETED MAIN DUCT AFTER REPAIR

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.

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