Radio - Speaker Noise With Radio Off
89cadillac03Bulletin No. T-89-70
File in Group 9
Number 56
Corp. Ref. No. 919601
Date Feb. 1989
WARRANTY INFORMATION:
SUBJECT: BUZZ/WHINE NOISE OVER BOSE SPEAKERS WITH RADIO OFF
MODELS AFFECTED: 1989 DE VILLES AND FLEETWOODS
Some 1989 DeVilles and Fleetwoods equipped with the Bose sound system, may experience a whine or buzz noise over the speakers with the radio turned off. This condition may be due to a shorted Bose amplifier relay supplying power to the speakers (turning them on).
To diagnose a vehicle with this condition, remove the Bose amplifier relay (relay "B" in the relay center) while the condition is present. If the noise is eliminated, measure the voltage at all four terminals of the relay socket. There should only be voltage at terminal 1 when the radio is off.
^ If there is voltage at more than one terminal, there is a short to voltage on the associated circuit. Repair circuit. Refer to Section 8A of the Service Information Manual.
^ If there is only voltage at terminal 1, replace the Bose amplifier relay.