For 1990-2009 cars

# ALTERNATOR WHINE-LEFT CHANNEL MODIFY GROUND TO RADIO

#### MODELS AFFECTED: 1985 AND 1986 ALL WITH 2000 VF RADIOS

The ground wire used in the instrument panel harness may cause a ground loop that may result in alternator whine heard in the left channel of the radio.

If alternator whine is heard, remove the ground lead (black wire) from the black 4-pin connector in the back of the radio. If the alternator whine disappears, correct the condition by doing the following:

1. Cut the black ground lead in the black connector.

2. Use a piece of 16 gauge wire, attach one end to the chassis of the radio and the other end to a good ground close to the radio. When attaching the wire to the radio chassis, use one of the chassis case screws or a mounting lug.

3. Reconnect the radio.

This will not eliminate all alternator whine conditions.

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.