PREVOST X3-45 2016 Maintenance Manual Download

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Section 06: ELECTRICAL

PA1593

8. A constant drain caused by a shorted circuit

such as an exposed wire or water infiltration
in junction boxes causing ground fault.

9. Failing to close disconnect switches during

the night.

3.8 TROUBLESHOOTING
If a battery is known to be good and then has
not performed satisfactorily in service for no
apparent reason, the following factors may
reveal the cause of trouble:

Vehicle accessories and disconnect
switches inadvertently left on overnight.

2. Defects in the charging system, such as

high wiring resistance, faulty alternator,
regulator or battery equalizer.

3. A vehicle electrical load exceeding the

alternator (or battery equalizer) capacity,
with the addition of electrical devices, such
as CB radio equipment, a cellular phone or
additional lighting systems.

4. Defects in the electrical system, such as

shorted or pinched wires.

5. Extended driving at a slow speed while

using many accessories.

6. Loose or poor battery cable-to-post

connections, previous improper charging of
a run-down battery, or loose hold-down
clamp bolts.

7. High-resistance connections or defects in

the cranking system.

3.9 “BATTERY VOLTAGE WARNING”

PICTOGRAM

If the

“

BATTERY VOLTAGE WARNING

(battery voltage incorrect) pictogram shows up
in the DID (Driver Information Display), check
the voltmeter gauge to determine if the battery
voltage is too high or too low.

3.9.1 Voltmeter Gauge Definitions

Voltmeter drops below 24.4 volts dc

Check alternator output.

Check voltage regulator.

Check battery connections.

Check battery cells.

Check battery equalizer connections.

Voltmeter exceeds 30 volts dc

Check alternator output.

Check voltage regulator.

Check battery connections.

Battery Balance

NOTE

Allow at least 15 minutes to balance batteries
after any corrective measure has been taken.

1. Batteries out of balance (difference greater

than 1.5 volts between the two battery
banks).

Check battery equalizer connections.

Check equalizer cables for proper gauge.

Check battery connections.

2. Demand for 12-volt power exceeding rated

amperage output of battery equalizers
causing batteries to go out of balance.

Reduce 12-volt load or install additional

battery equalizer(s).

4. TROUBLESHOOTING AND TESTING THE

MULTIPLEX VEHICLES

4.1

ELECTRICAL SYSTEM DIAGNOSTIC

Using the Driver Information Display (DID),
check if there are active errors in the vehicle
electrical system. With the

Diagnostics

menu,

highlight

Fault Diagnostics

and then highlight

Electrical System

to request a diagnostic of the

electrical system from the MCM. Press the enter
key. If applicable, the DID shows the multiplex
device ID, the fault messages or fault codes
recorded. When more than one fault is recorded,
an arrow pointing down appears on the right of
the display. Use the down arrow to see all the
fault messages.
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. The
MCM can store up to 20 faults, i.e. the first 10
and the last 10. Middle faults will be erased. If
the breakers are tripped, the fault history will be
erased from the MCM memory.