PREVOST X3-45 COMMUTER User Manual

SECTION 22: HEATING AND AIR CONDITIONING
DOB 1300-1556 | X3-45 Commuter PA-1648 Maintenance Manual First release Oct 2020
35
Problem/Symptom
Probable Causes
Actions
HVAC condenser fans not
functioning in speed 2
Circuit breaker CB7 tripped
Seized bearing
Bad wiring
1. Check / reset circuit breaker CB7
2. See HVAC condenser fans not functioning
& HVAC condenser fans not functioning in
speed 1 above.
Defroster fan is functioning
but no heat or cooling
available in the driver’s area
Module AE46 is not powered or
is faulty
Bad wiring
1.
Check the Diagnostics menu of Driver
Information Display (DID). Select Fault
Diagnostics and Electrical System. The
message “No Response ModAE46,
Active” indicates a power problem on the
module. (A CAN network problem would
show the same message but doesn't
produce these symptoms).
2. Check / reset circuit breaker CB1
3. Check CB12V or CB13V (VECF)
4. Probe gray connector on module to see if
it is powered.
The A/C compressor clutch
does not engage
Module AE52 is not powered or
is faulty
1.
Check the Diagnostics menu of Driver
Information Display (DID). Select Fault
Diagnostics and Electrical System. The
message “No Response ModAE52,
Active” indicates a power problem on the
module. (A CAN network problem would
show the same message but doesn't
produce this symptom).
2. Check / reset circuit breaker CB5
3. Check CB65V (VECR)
4. Probe gray connector on module to see if
it is powered.
Evaporator fan not
functioning
Circuit breaker CB3 tripped
Module AE54 is not powered or
is faulty
1. Check / reset circuit breaker CB3
2.
Check the Diagnostics menu of Driver
Information Display (DID). Select Fault
Diagnostics and Electrical System. The
message “No Response ModAE54,
Active” indicates a power problem on the
module. (A CAN network problem would
show the same message but doesn't
produce this symptom).
3. Check / reset circuit breaker CB5
4. Check CB67
5. Probe gray connector on module to see if
it is powered.
6.
Check / replace condenser power relay
R12 (pro
be R12 coil power circuit 67,
should be 24 volts).

PREVOST X3-45 COMMUTER Specifications

General

Engine	Volvo D13
Transmission	Allison B500
Fuel Type	Diesel
Length	45 ft (13.7 m)
Width	102 in (2.6 m)
Horsepower	500 hp
GVWR	54, 000 lbs
Height	141 in