The J 39500 A/C Refrigerant Recovery, Recycling, and Recharging (ACR4) removes the Refrigerant-134a from the vehicle A/C system. There is one filtering cycle during recovery plus an automatic multiple pass filtering during the evacuation cycle, ensures a constant supply of clean/dry refrigerant for the A/C system charging.
Refer to the J 39500 ACR4 manual for operation and setup instructions.
Circuit Operation
When the ignition switch is in the RUN position, the Blower Motor Relay is activated and battery voltage is applied to the HVAC Control Head from the BLO MOT maxifuse 49 through circuits 42 and 1342. The HVAC Control Head provides 6 electrical contacts with the Blower Motor Control Module. These 6 contacts vary the voltage drop across the variable Blower Motor (i.e., the greater the voltage drop across the Blower Motor the faster its speed). The Blower Motor and the Blower Motor Relay are grounded through circuit 150 to Splice Pack #202, SP202.
Circuit Operation
The compressor for the air conditioning system is belt-driven by the engine through the A/C Compressor Clutch. The Powertrain Control Module (PCM) controls the A/C Compressor depending on the HVAC Programmer Module mode and temperature settings. The PCM controls the A/C Compressor Clutch by activating the A/C CLU micro relay 34.
When the PCM receives a A/C request from the HVAC Programmer Module through circuit 762, it activates the A/C CLU micro relay 34 through circuit 459. The battery voltage is applied from the A/C mini fuse 24 and A/C micro relay 34 to the A/C Compressor Clutch through circuit 59. Circuit 59 also carries the A/C Compressor status to the PCM. The A/C Diode prevents current flow that could damage A/C Compressor Clutch components. The A/C Compressor Clutch is grounded through circuit 150 to Splice Pack #100, SP100.
The PCM uses the A/C Refrigerant Pressure Sensor to control refrigerant pressure. If the refrigerant pressure is too high (i.e., could cause engine overheating), the PCM disengages the A/C Compressor Clutch. The A/C Refrigerant Pressure Sensor sends refrigerant pressure data to the PCM through circuit 380. Circuit 407 supplies the A/C Refrigerant Pressure Sensor with ground voltage, and circuit 474 supplies 5V reference voltage.
