Heater and Air Conditioner, R 134a Systems 83.03

Transcription

1 Heater and Air Conditioner, R 4a Systems 8.0 WARNING R 4a is the only refrigerant that is approved for use on Freightliner LLC vehicles. Several companies offer less expensive, hydrocarbonbased refrigerants, such as propane and methane. Use of these refrigerants will void the warranty on the vehicle s air conditioning system, cause damage to the air conditioning system, and possibly result in personal injury or property damage. Leaking air conditioning systems charged with hydrocarbon-based refrigerants pose a serious risk of fire or explosion under the hood, or inside the passenger compartment. Regardless of what the refrigerant supplier states, no vehicle built by Freightliner LLC can be safely charged with hydrocarbon-based refrigerants. When servicing an air conditioning system, be sure to use a refrigerant identifier to ensure that the system has not been charged with something other than R 4a. This should be standard practice since there is no way to tell what services have been previously performed. Identification by service technicians will help to avoid the risk of explosion and guard against contamination of equipment when refrigerant is recovered and recycled. See Fig. for the air conditioning wiring diagram. See Fig. for the air conditioning plumbing diagram. See Fig. for the heater plumbing diagram for Cummins B Series engines. See Fig. 4 for the heater plumbing diagram for Cummins C Series engines. See Fig. 5 for the heater plumbing diagram for Mercedes-Benz OM 66LA engines. See Fig. 6 for the heater plumbing diagram for Dodge Magnum engines. See Fig. 7 for the APADS electronic control module wiring diagram. See Fig. 8 for the Cummins mechanical engine and APADS schematic. Torque Values Description Torque lbf ft (N m) lbf in (N cm) Expansion Valve Fittings: Evaporator Large Line 4 () Evaporator Small Line 8 (4) Receiver-Drier Line (6) Refrigerant Compressor Line 8 (4) Blower Motor Mounting Nuts 7 (9) Condenser Mounting Bolts 5 (0) Condenser Refrigerant Line Fittings (45) Receiver-Drier Fittings (45) Binary Switch 08 (0) Table, Torque Values Business Class Trucks Service Manual, Supplement, September /

2 8.0 Heater and Air Conditioner, R 4a Systems Ambient Air Temperature F ( C) Target Humidity Temperature/Pressure Actual (Relative Humidity) Dash Louver Temperature F ( C) Service Port Pressures * High (psi) Low (psi) A/C Compressor Cycling On? 70 () Low 5% 44 (6) Yes 70 () High 55% 45 (7) Yes 80 (7) Low 5% 46 (8) Yes 80 (7) High 55% 5 () No 90 () Low 5% 49 (9) No 90 () High 55% 60 (6) 4..5 No 00 (8) Low 5% 57 (4) No 00 (8) High 55% 68 (0) No * Service port pressures recorded with A/C compressor running. Fresh air mode in use. Table, Temperature/Pressure /4- and 5/8-Inch Heater Hose Clamp Torque Values Description Torque lbf in (N cm) Standard Hose Clamp 40 (45) Worm-Gear Hose Clamp 40 (45) Breeze Constant-Torque Hose Clamp 40 (45) Oetiker Constant-Torque Hose Clamp 8 (0) Table, /4- and 5/8-Inch Heater Hose Clamp Torque Values APADS Parametric * Parameter Minimum Typical Maximum Units Supply Voltage (continuous operation) Volts Supply Voltage (absolute maximum, two minute duration) 4.0 Volts Supply Current (no load) 50.0 mamps Load (AC clutch drive) Ohms Load (AC clutch drive) Henries Load Energy ½LI.5 Joules Relay Contact Voltage Drop Volts Load (fan actuator circuit).0 Ohms Load (fan actuator circuit) 80.0 mhenries Input Debounce Delay 0.. Seconds 400/ Business Class Trucks Service Manual, Supplement, September 005

3 Heater and Air Conditioner, R 4a Systems 8.0 APADS Parametric * Parameter Minimum Typical Maximum Units Open Clutch Sense Current Amps Shorted Clutch Cut Out Resistance.7.4 Ohms Voltage Cut Out Off Threshold Volts Evaporator Thermostat On Range 5.0 VIGN Volts Evaporator Thermostat Off Range 0.0 Volts * Applicable over the full operating range: 40 to F ( 40 to 00 C) All voltages referenced are to ground lead of the device. Table 4, APADS Parametric Business Class Trucks Service Manual, Supplement, September /

4 8.0 Heater and Air Conditioner, R 4a Systems A A A H M L 98L 98Z 98Y 98E 98Z 0 98Z 98Z R 98Z T 7 04/5/94 NOTE: For the specific location of each circuit breaker/fuse/relay in the electrical center, refer to the Wiring Diagram and Circuits, Vehicle section in Group 54. A. To circuit 4. 0A. 5A. 40A 4. Heater/Air-Conditioner Relay 5. Resistor 6. Heater Blower Relay 7. Blower Motor Fig., Air Conditioning Wiring 8. Compressor Clutch Relay 9. Thermostatic Switch 0. Defroster/Dehumidifier Microswitch. Blower Motor Switch. Air Conditioner On/Off Microswitch. Binary Switch 4. Air Conditioner Compressor Clutch f54049a 400/4 Business Class Trucks Service Manual, Supplement, September 005

5 Heater and Air Conditioner, R 4a Systems /5/94. Condenser. Refrigerant Compressor. Thermostatic Switch 4. Evaporator Coil 5. Expansion Valve Fig., Air Conditioner Plumbing 6. Extension Hoses (through frontwall) 7. Binary Switch 8. Moisture Indicator 9. Receiver-Drier f8070a Business Class Trucks Service Manual, Supplement, September /5

6 8.0 Heater and Air Conditioner, R 4a Systems //9. Heater Return Line. Surge Tank Hose. Heater Supply Line f8057 Fig., Heater Plumbing for Cummins B Series Engines 400/6 Business Class Trucks Service Manual, Supplement, September 005

7 Heater and Air Conditioner, R 4a Systems 8.0 A //9 A. To radiator shunt line.. Heater Return Line. Heater Supply Line. Surge Tank Hose f8058 Fig. 4, Heater Plumbing for Cummins C Series Engines Business Class Trucks Service Manual, Supplement, September /7

8 8.0 Heater and Air Conditioner, R 4a Systems //9. Heater Return Line. Heater Supply Line. Surge Tank Hose 4. Radiator Outlet Hose Fig. 5, Heater Plumbing for Mercedes-Benz OM 66LA Engines 4 f /8 Business Class Trucks Service Manual, Supplement, September 005

9 Heater and Air Conditioner, R 4a Systems 8.0 A 0/0/95 f8067 A. To the heater.. Heater Supply Line. Water Regulating Valve. Heater Return Line Fig. 6, Heater Plumbing for Dodge Magnum Engines A/C COMPRESSOR CLUTCH GROUND A + VDC BLUE RED ORG BLACK GREEN WHITE WHITE/BLK YELLOW GROUND ECM OR FAN SOLENOID CAB TSTAT A/C ON/OFF + VDC LOW PRESSURE SWITCH 08//98 YELLOW/BLK HIGH PRESSURE SWITCH f88 Fig. 7, APADS Electronic Control Module Wiring Diagram Business Class Trucks Service Manual, Supplement, September /9

10 8.0 Heater and Air Conditioner, R 4a Systems Ref. Diag. D //98 f54688 Fig. 8, Cummins Mechanical Engine and APADS Schematic 400/0 Business Class Trucks Service Manual, Supplement, September 005