PREVOST LE MIRAGE XLII BUS SHELLS, Maintenance Manual

Page: 1094 / 1260

Section 22: HEATING AND AIR CONDITIONING
PA1564
26
(3/8 inch) between the brush face and a
reference line passing through the center of
the 2 bolts on the motor housing.
CAUTION
If rotating the rocker ring is necessary, it is
preferable to mark off the angular position of
the rocker ring before unfastening the bolts
fixing the mechanism in order to get back to
the factory setting at the end of the operation.
NOTE
Take a final reading in 1
st
and in 2
nd
speed
after tightening the brush holder bolts. The
amperage may have changed.
FIGURE 30: EVAPORATOR MOTOR
22321
CAUTION
To avoid damaging the motor, make sure all
vehicle doors are closed when taking the
readings.
9.3.7 Checking Commutator
The surface must be polished. A brown-black
colored surface is normal and indicates a good
switching. Ensure there is no evidence of arcing
or metal chips.
9.4 CONDENSER
The central A/C system condenser coil is hinge
mounted on the R.H. side of the vehicle on the
A/C condenser door (Fig. 32). Since
condenser’s purpose is to dissipate heat from
the hot refrigerant, it is important to keep the
cooling coils and fins clean. A clogged coil will
cause high discharge pressure and insufficient
cooling.
9.4.1 Condenser Fan Motors
Two fan motors (Fig. 31), 28.5 V - (0.6 HP - 0.42
kW) and cages are installed in the condenser
compartment on R.H. side of vehicle in order to
ventilate the condenser coil. They are mounted
on a support, fastened to the floor. The fans pull
outside air through the condenser coil and
discharge it through an opening at bottom of
compartment. When temperature drops inside
condenser, the pressure in the refrigerant line also
drops and it is, therefore, no longer required to
cool condenser. Consequently, when pressure
drops to 130 psi, the motors will run at low speed
and if the pressure continues to drop to 90 psi, a
pressure switch stops the motors so that fans do
not operate needlessly. When pressure rises to
120 psi, the pressure switch reactivates the
motors. If the pressure rises to 170 psi, the motors
will switch to high speed.
For details about electrical wiring, refer to
“A/C
and Heat system” in the master wiring diagram.
FIGURE 31: CONDENSER FAN MOTOR
22234
9.4.2 Condenser Fan Motor Removal
1. Set the ignition key switch to the “Off”
position.
2. Remove the two “Phillips” head screws
retaining the fan motor protective cover to
the square tubing. Remove the protective
grill from mounting support.
3. Disconnect wiring from terminals on motor.
Tag each wire to aid in identification at time
of reconnection.
4. Support motor, and remove bolts which
attach motor to mounting bracket. Remove
the motor.
9.4.3 Preliminary Disassembly
1. Remove the brushes.