SERVICE MANUAL UPDATE SEC. 8A ELECTRICAL SYSTEM DIAGNOSIS

SUBJECT: MANUAL UPDATE - SECTION 8A ELECTRICAL DIAGNOSIS (REFER TO 1989 MANUAL ADAPTOR WIRING DIAGRAM)

VEHICLES AFFECTED: 1990 'B' OLDSMOBILE CUSTOM CRUISER

Some Early Production 1990 Oldsmobile Custom Cruisers were produced with trailer adaptor wiring. The trailer adaptor wiring was not included in the 1990 "B" Carline Service Manual. For a circuit diagram and diagnosis description of the trailer adaptor wiring for 1990, refer to the 1989 "B" Carline Service Manual Section 8A-118.

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.