Some early production 1988 Toronado models were built with a muting circuit from the BCM to the radio. This circuit was used in the 1986 and 1987 Toronado when the voice module was an option, however it has been discontinued for 1988. This circuit can cause the radio to mute intermittently due to the voltage present on it.
To repair this condition, it is necessary to locate the dark green/orange wire in cavity Al of the center BCM connector and cut the wire at the connector. Then tape the wire back so it cannot short. This is accessible through the glove box opening.
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.