TAILGATE WINDOW DEFOG. NOT FUN (REPL. GLASS LIFT/SUPPORT CYL). GMC Truck S15 Pickup - 2WD 1991

For 1990-2009 cars

# TAILGATE WINDOW DEFOG. NOT FUN (REPL. GLASS LIFT/SUPPORT CYL)

#### SUBJECT: TAILGATE WINDOW DEFOGGER WILL NOT FUNCTION (REPLACE TAILGATE GLASS LIFT/SUPPORT CYLINDERS) MODELS: 1983-91 S/T UTILITY WITH RPO ZM8

Owners of some 1983-91 S/T Jimmys may comment that the tailgate window defogger will not function.

This condition may be caused by an electrical failure at the tailgate glass support/lift cylinder connection caused by the improper orientation of the wiring male connector to the tailgate glass lift cylinder. A redesigned glass lift cylinder has been released to eliminate this condition. Previously only one cylinder was released for both sides of the glass. To insure proper orientation of the male connector, separate part numbers are now required for the right and left cylinders.

SERVICE PROCEDURE

1. Inspect the wiring for breaks at or near the glass lift cylinder connections.

2. Repair the wiring using procedures outlined in section 8A of the 1992 SfT Service Manual.

3. Replace the glass lift cylinder(s) with the redesigned cylinder(s) using correct part number(s) for the right and left cylinders.

4. Close the tailgate glass and verify that the wiring is not trapped between the glass and the weatherstrip. Reposition the wiring if required to prevent water intrusion.

SERVICE PARTS INFORMATION

PART NUMBER DESCRIPTION QTY

15688545 Tailgate Glass Support/Lift 1 Cylinder, Right

15688546 Tailgate Glass Support/Lift 1 Cyinder, Left

Parts are currently available from GMSPO.

WARRANTY INFORMATION

For vehicles repaired under warranty use:

LABOR LABOR OPERATION DESCRIPTION TIME

N6440 Rear Defogger Wiring/ ST Connector Repair C0740 Replace Tailgate Glass .2 HR Support, Right C0741 Replace Tailgate Glass .2 HR Support, Left C0747 Replace Tailgate Glass .3 HR Support, Both

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.