PREVOST X3-45 2016 Maintenance Manual Download

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Section 06: ELECTRICAL

PA1593

Problem:

DID displays the fault "Elec. Horn

SW61 SW62; shorted to ground" as being
active.
a) Refer to wiring diagram index, and look for

"Multiplexed Device Index"

, pages B1-B8.

b) In first column DEVICE ID, look for device

SW61, SW62.

c) At device SW61,SW62, find the fault

message, the minimum condition to activate,
other inputs involved in logic, the multiplex
module related to switch 61 and switch 62,
the connector and pin number on the
module and the page on which to find the
corresponding diagram.

d) Once the problem corrected, the DID still

shows the fault as being active. You have to
leave the

Fault Diagnostics

menu, wait

approximately 20 to 30 seconds and then
return to

Fault Diagnostics

to request a

new diagnostic of the

Electrical System

from the MCM. The DID should display the
fault as being inactive.

1.1.2 Testing

Circuits

A careful study of the wiring diagrams should be
made to determine the source and flow of
current through each circuit. When a circuit is
thoroughly understood, a point-to-point check
can be made with the aid of the applicable
wiring diagrams. Any circuit can be tested for
continuity or short circuits with a multimeter or a
suitable voltmeter.

All electrical connections must always be kept
clean and adequately tight. Loose or corroded
connections can result in discharged batteries,
difficult starting, dim lights and improper
functioning of other electric circuits. Inspect all
wiring connections at regular intervals. Make
sure knurled nuts on all amphenol-type plugs
are securely tightened. Knurled nuts on the
plastic amphenol-type connectors will click into a
detent when properly tightened. Line
connectors, who have the side locking tabs,
must have the locks latched in place to ensure a
proper electrical connection.

1.2

WIRE SIZES AND COLORS

Each wire in the electrical system has a specific
size as designated on the wiring diagram. When
replacing a wire, the correct size must be used.
Never replace a wire with one of a smaller size.
The vehicle electrical system is provided with
different voltages. The insulation on each wire is

distinctly colored in order to determine visually
the wiring voltage and to assist in making
connectors. The wires are color coded as
follows:

Yellow Multiplex

modules

communication

CAN-H (twisted with green)

Green Multiplex

modules

communication

CAN-L (twisted with yellow)

Orange

Connected to multiplex outputs

White

Connected to multiplex inputs

Red

24 volt system

Yellow

12 volt system

Black grounded

wire

Blue

110 V ac system (live)

White

110 V ac system (neutral)

Green

110 V ac system (ground)

Orange

speakers (+) (

Coaches Only)

Brown

speakers (-) (

Coaches Only)

Grey spare

wire

NOTE

Wires are identified at each 2-4 inch (5-10 cm)
intervals by a printed number.

Each wire on a diagram is patterned to assist in
tracing and testing circuits. The wire number
identifies the voltage rating, the wire identification
number and the basic wire gauge as illustrated in
figure 1.

FIGURE 1: WIRE IDENTIFICATION

06048

1.3 SPARE

WIRES

When the vehicle leaves the factory, and even in
the case of a fully-equipped vehicle, an
important number of unconnected spare wires
are routed between the junction boxes.
Consequently

, for any connection of an additional

accessory, look in Wiring Diagram for “spare” wires
in the circuit number listing of pages E.1 thru E.8 to
determine the circuit number. Refer to page 8.1 in
Wiring Diagram to find location of these wires.

CAUTION

Wire size is calibrated according to the breaker or
fuse that protects it. When using a spare wire to
replace a damaged wire, assure that the spare wire
size is equal or larger than the wire being replaced.
Using a wire too small for the breaker or fuse
amperage might cause overheating of the wire.