AM Radio Diagnostics, Interference
1Information and explanation
Radio noise at 11-6 MPH on AM
S80 Chassis - 049149
See SB 39-0010
General Static/crackling noise (helicopter noise)
S80 Chassis - 116810
UEM processor sound being heard in the audio system. UEM has a long ground wire which in some cases can act as an antenna. Replace the interior light housing complete (see step 2).
Static noise - Volvo navigation system (VNS)
V70 Chassis no. 000257-
If a seek lest gives the same number of clearly audible AM stations but a "static" sound is heard while using the Volvo Navigation System (VNS) install a grounded shield on the VNS wiring and connector (see step 2). The amount of static can depend on the contrast level of the screen being viewed.
Intermittent pulsing, buzzing sound with seat heater
on
S80 Chassis no 029668-147860
V70 Chassis no 000257-026213 Torslanda
V70 Chassis no -028000 Gent
V70XC Chassis no -000907
A pulsing, buzzing noise may be heard from the radio on AM frequency if seat heater is activated. As a service solution an adapter cable with a 180-Ohm resistor must be connected in series to control module for the seat healer. One adapter cable must be used for each seat (see step 7-10).
AM static due to insufficient rear seat ground
Install the ground lead see step 11-17.
Ticking radio interference sounds of approximately one second interval might appear on the AM band due to insufficient grounding of the rear plate of the back seat. This radio interference could be reduced if the framework of the seat back is given an improved grounding to the car body.
Replacing the interior light housing (Chassis no. see step 1, "Information and explanation")
2
Interior light housing, replacing
Replacing the interior light housing, see VADIS
Repair and Installation
Function group 35
Courtesy lighting and the upper electronic module.
Install the:
- ground wire (1) from the service kit to the new interior light housing
- new interior light housing in the car
Note
Make sure that the ground wire does not get pinched between the clip and the ceiling (see arrows)
Install grounded shield on VNS connector and wiring (Chassis no., see step 1, "Information and explanation")
3
Grounded shield, installing
Remove the:
- rear left panel cover and the cargo compartment left panel, see VADIS
Repair and Installation Function group 85
Cargo compartment side panel cover and the side panel in the cargo compartment
- connector (1)
- screw (2).
4
Assemble the shield.
5
Install the shield on the connector.
6
Install the:
- connector (3) to the VNS unit
- ground wire (1) with screw (2). Adjust the shield
- front left panel.
Note!
Ensure that the shield is pushed up against the VNS unit when installed to minimize interference.
Install adapter cable on front seats
(Chassis no, see step 1, "Information
and explanation")
7
Adapter cable, installing
Preparations
Move the seat to the rear-most position.
Raise the front of the seal to the upper-most position
Remove the key from the ignition switch.
8
Disconnecting the connector (power adjustable seats)
Disconnect the seat heater wiring plug (1) from its socket.
9
Installing the adapter wiring (power adjustable seats)
Plug the:
- adapter wire into the socket at the bracket (2)
- seat heater wiring plug into the adapter socket (1).
10
Secure the wiring and resistor with tie straps 11). Check that wiring and connectors are not in contact with any other components and that they do not rattle.
Install the rear seat ground lead (Chassis no, see step 1, "Information and explanation")
11
Removing the battery negative terminal
Disconnect the battery negative terminal, see VADIS:
Repair and installation
Function group 31
Replacing the battery.
12
Removing the left-hand side cushion
Fold the backrest cushion for the rear seat forward. Grip the side cushion as close to the upper mounting as possible.
Pull the cushion until it releases. Lift the cushion up out of the lower mounting.
13
Removing the left-hand side backrest cushion
Fold the backrest cushion up.
Disconnect the connector for the seat belt tensioner by the outer mounting for the backrest.
Detach the half moon clip and ring holding the seat belt buckle in place.
Remove the screw holding the backrest cushion. Detach the backrest cushion. Position the backrest cushion in the door opening in order to access the lower edge of the backrest (1) cushion from the outside. (See the illustration).
14
Exposing the back panel
Remove the:
- five half moon clips from underneath the cushion
- guide for the inner mounting for the cushion. Undo the tie strap at the inner edge of the backrest upholstery.
Push the upholstery and padding to one side to access the clip holding the wire for the seat belt tensioner.
Disconnect the wire from the clip.
15
Installing the ground lead in the back panel
Drill a 5 mm hole in the plate between the clamp for the backrest mounting and the clip for the wire for the seat belt tensioner.
Position the hole approximately 15 mm (0.6 ) from the clip.
Remove any burs.
Install the:
- ground lead using screw p/n 958244. Route the ground lead along the existing wire through the backrest upholstery
- cable for the seat belt tensioner in the clip.
16
Installing the backrest cushion
Push the padding and upholstery back into position. Pull the tie strap closed at the inner edge of the backrest upholstery.
Install the:
- guide for the inner mounting for the cushion
- inner half moon clip and ring for the strap for the seat belt
- remaining half moon clips
- backrest (1). Tighten to 48 Nm (35 lbf.ft).
Connect the seat belt tensioner connector.
Install the strap for the seat belt buckle.
17
Connecting the ground terminal
Fold up the insulation panel under the rear seat.
Remove the rear ground terminal 31/47.
Install the ground lead together with the removed wiring using a new screw from the kit. Tighten the screw.
Tighten to 10 Nm (7 lbf.ft).
Fold the:
- insulation back into place
- rear seat back into position.
Install the battery negative terminal, see VADIS:
Repair and installation Function group 31 Replacing the battery.
Discard the excess material from the kit.