A 1986 Eldorado Biarritz equipped with Delco/Bose radio (option VQ4) may exhibit a speaker buzz or whine when both the radio and exterior lights are on; the opera lamps may also appear dim or be inoperative. This condition may be caused by the AC/DC inverter contained in the opera lamp assemblies.
An opera lamp voltage inverter can be diagnosed as the source of the noise by disconnecting each individual lamp connector. The radio noise will stop when the effected lamp is unplugged. Either the left, right or both lamps can be the cause.
To repair the radio noise condition, replace the effected opera lamp assembly. The lamp assembly part numbers are 919308 (RH) and 919307 (LH).
Use the following procedure to gain access to the opera lamp connectors and opera lamp assemblies for diagnosis or replacement.
Tools Required: Trim Pad Remover J-24595B or BT-7323A or equivalent.
1. Speaker covers, speakers, back panel of rear seat (rear compartment side), rear seat cushion and seatback (refer to Section 9D of the 1996 Body Service Manual).
2. Loosen front carpet retainer (refer to Section 3D of the 1986 Body Service Manual), seat belt retractor cover and remove screw securing forward edge of rear carpet retainer.
3. Rear carpet retainer.
4. Assist strap covers and screws.
5. Armrest and loosen quarter trim panel.
6. Disconnect courtesy lamps and remove quarter trim panel.
7. Remove clips securing opera lamp and trim assembly. Remove assembly from quarter panel, disconnect and remove opera lamp.
8. To reassemble, reverse steps 1-8.
For warranty purposes, use labor operation N1510 at .7 hours for the right opera lamp and N1511 at .7 hours for the left opera lamp.
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.