The 1988 and early 1989 Grand Prix models used a power window/power door lock switch assembly with a separate module attached. The module contained the electronics to operate the power window "express down" feature.
In mid-year 1989, the switch was redesigned, with the "express down" electronics built into the switch body, eliminating the separate module. The new switch is interchangeable with the old switch, by simply cutting the module off the old switch, and leaving it in the door.
1. If the power window/power door lock switch assembly needs to be replaced, remove the old switch assembly from the door, following the instructions in Section 5W of the Body Section of the Service Manual. Disconnect the wire harness connectors.
2. If the switch assembly has a module attached, cut off the wire harness to the module, and discard the old switch assembly. Secure the module wire to the door trim panel with tape, so that it will not rattle.
3. If there is no module attached to the switch, the parts are interchangeable, and no further action is required.
4. Install the wire harness connectors, and reinstall the new switch assembly into the door.
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.