The 1988 DeVille and Fleetwood air conditioning compressor control circuit was changed at approximate VIN breakpoint 260000.
The attached pages, Section 8A Cell 64, detail the control circuit changes which will appear in the DeVille/Fleetwood Final Edition Service Information Manual. The circuit was changed to eliminate the A/C RELAY in the interior relay center. Both early and late production circuits are shown on the attached pages.
This information is provided for use until the 1988 Final Edition Service Information Manual is available.
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.