PREVOST X3-45 2016, Руководство по обслуживанию

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Section 06: ELECTRICAL
PA1593
7
Electrical Center Front) and VECR (Vehicle
Electrical Center Rear).
1.7 RELAYS
Relays are used to automatically energize or
deenergize a circuit from a remote location. The
relay draws a very low current to energize its
coil. Once the coil is energized, it develops a
magnetic field that pulls a switch arm closed or
open, to either energize or deenergize a given
component. As the control current required for
the coil is very low, the relay allows a remote
station to control a high energy circuit without
running great lengths of costly high capacity
cable, and also eliminates the need for high
amperage switches and heavy connectors.
NOTE
Each relay is identified with “12V” or “24V”
printed on its casing in order to identify the
coil operating voltage.
CAUTION
The Multiplex vehicle uses a VF4 relay
designed specially for Volvo that has different
internal characteristics than the current VF4
relay. It is important to use only the new part
marked Volvo as a replacement in Multiplex
vehicles. Regular relays have an inadequate
lifespan for Multiplex vehicles.
1.8 PRECAUTIONS
DANGER
Prior to working on a system inside vehicle,
make sure to cut electrical power and air
supply. A component could be supplied with
electricity even if the ignition switch is set to
the OFF position and/or a component could
be pressurized even if air tanks are emptied.
Always refer to the appropriate wiring and
pneumatic diagrams prior to working on
electrical and/or pneumatic systems.
NOTE
When the ignition switch is set to the OFF
position, the electrical components are not
energized except for the MCM (Master
Chassis Module), ECM (Engine Control
Module), TCM (Transmission Control
Module), instrument cluster module, the
battery equalizer, the wheelchair lift system
and some Multiplex modules which are
energized during 15 minutes after the ignition
has been set to the OFF position. Prior to
working on one of these electrical components,
set the master cut-out switch located above the
rear electrical panel to the OFF position.
If the vehicle will not be operated for a long
period (more than 2 weeks), it is
recommended, in order to prevent the batteries
from discharging, to trip main circuit breakers
(2, 4 and 6) located on the rear junction panel
to stop the small current drawn by the radio
preset station memory, the MCM memory and
the instrument cluster clock. Note that the radio
station presets will be erased, same thing for
the diagnostic codes history and the instrument
cluster clock will have to be reset.
CAUTION
Prior to arc welding on the vehicle, refer to
"Multiplex Modules Disconnection Procedure
Prior To Welding" in section 00 GENERAL of
this manual to avoid serious damage to the
vehicle components.
Black
Blue Green
Green
Grey
Orange
Black
Red
Grey
Brown
Green
Yellow
1
2
1
5
14 30 14 30
1 15 15 1
1
11
20
13
23
15
14
4
5
16
17
18
19
10
29
Guides, not
terminal
cavities
A
B C D
E
F G H
24
BACK PROBING VIEW
FIGURE 3: MULTIPLEX MODULE CONNECTORS PIN-OUT
06624