780 V6-2849cc 2.8L SOHC B280F (1987)
Grounding Point: All Technical Service Bulletins
Radio - Buzzing Noise
Group
39
No.
111
Date
January 1990
THIS SERVICE BULLETIN APPLIES TO U.S. AND CANADA REFERENCE: TP 31208/1 (ENGLISH); FAULT TRACING RADIO
Radio interference may occur in some 780's while the engine is running. This interference changes with the engine RPM, and sounds like a buzzing
noise.
The reason for this may be a bad ground for the front amplifier, located on the reinforcing panel. The amplifier is grounded through this reinforcing
panel.
To improve the ground, extend the ground wire (use 2.5 mm 2,14 gauge wire) and route it down (following other harnesses) to the lower left door hinge
area.
PROCEDURE:
^ Turn ignition "OFF".
^ Disconnect the battery ground (-) cable.
^ Remove knee bolster and reinforcing panel.
^ Unscrew the ground terminal from the reinforcing panel and cut off the terminal.
^ Using Volvo Tool 9324 or equivalent, add a new length (approximately 40") of 14 gauge black wire to the existing ground wire from the amplifier
using splice terminal (Volvo P/N 956958).
^ Route the wire alongside the dash-harness down to the ground point at left A-Pillar. Secure the wire with electrical tape or tie straps to the other
harnesses.
