Test Sequence; Forced Activation Of The Radiator Fan Clutch - PREVOST X3-45 2016 Maintenance Manual

Section 06: ELECTRICAL
SEQUENCE and press ENTER button to
initiate the test mode for electrical motors;
3. Ten (10) beeps can be heard indicating the
motor test mode has started.
Using the test mode:
During the entire test, the instrument panel
audible alarm gives a signal each second to
remind that the motor test mode is underway.
4.4.1

Test Sequence

Go to the condenser compartment:

The condenser fans start at speed 1, then
after a short pause, speed 2 activates.

The passenger's unit refrigerant solenoid
valve activates.
Then 5 beeps can be heard from the back-up
alarm to indicate to go to the engine
compartment.
In the engine compartment, the sequence is
as follows:

Toilet fan motor starts.

A/C compressor clutch activates 3 times.

Left compressor unloader activates 3 times.

Right compressor unloader activates 3
times.

Fan clutch is disengaged (fan can be turned
freely by hand).

Fan clutch engages in speed 1 (fan can be
turned by hand
resistance).

Fan clutch engages in speed 2 (cannot be
turned but hand).
5 beeps from the back-up alarm indicate to go to
the evaporator compartment.
In the evaporator compartment:

Evaporator fan motor runs at speed 1 for 3
seconds then runs at speed 2 for 2 seconds.

Hot water pump starts running for 5 seconds
and hot water pneumatic valve cycles 3
times.
5 beeps from the back-up alarm indicate to get
to the driver's area inside the vehicle.
20
but with a certain
Inside the vehicle:

The driver's HVAC unit refrigerant solenoid
valve cycles 3 times and the hot water
pneumatic valve cycles 3 times also.
To exit the electric motors test sequence,
press ESCAPE button, select STOP TEST
submenu and then press ENTER button
twice.
4.5 FORCED
RADIATOR FAN CLUTCH
To prevent the engine from overheating in case
of malfunction of the clutch activation system, it
is possible to force activation of the clutch.
1. On the Driver Information Display, select
DIAGNOSTICS menu. Select VEHICLE
TESTS submenu and then ACTIVATE
RADIATOR FAN SPEED 1 or ACTIVATE
RADIATOR FAN SPEED 2 as required.
2. The DID status line will show TEST to
confirm the forced activation of the radiator
fan clutch. To cancel, turn the ignition
switch to the OFF position or press
ESCAPE
submenu and then press ENTER button
twice. TEST will disappear from the DID
status line.
If the fan clutch does not engage using this
procedure then the clutch is faulty or the wiring
between the multiplex module and the clutch is
faulty. Mechanically lock the fan clutch as
described in section 05: COOLING SYSTEM of
the maintenance manual.
PA1593
ACTIVATION OF
button, select STOP
THE
TEST