Some 1987-1991 Broughams may experience a popping noise over the radio speakers when the windshield wipers are on as the ignition is turned on or off. This condition may be caused by electrical interference between the wiper/washer assembly and radio receiver power feed circuits. To repair this condition install a diode jumper harness, P/N #12070676, between the C1 connector and the windshield wiper motor as shown in Figure. 1.
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.