NEED TO KNOW VOLTAGE ON SWITCH AT THE ACCUMALTOR
This is the explanation of the circuit, some information is from the Alldata information website. If you need a full explanation of the A/C operation you can get it at ALLDATAdiy.com.
If you need any other information I'll be glad to help.
A/C Refrigerant Pressure Sensor:
The A/C refrigerant pressure sensor is a 3-wire piezoelectric pressure transducer. A 5-volt reference, low reference, and signal circuits enable the sensor to operate. The A/C pressure signal can be between 0-5 volts . When the A/C refrigerant pressure is low, the signal value is near 0 volts . When the A/C refrigerant pressure is high, the signal value is near 5 volts . The PCM converts the voltage signal to a pressure value.
The A/C refrigerant pressure sensor protects the A/C system from operating when an excessively high pressure condition exists. The PCM disables the compressor clutch if the A/C pressure is more than 2957 kPa (429 psi) . The clutch will be enabled after the pressure decreases to less than 1578 kPa (229 psi) .
A/C Low Pressure Switch:
The A/C low pressure switch protects the A/C system from a low pressure condition that could damage the A/C compressor or cause evaporator icing. The HVAC control module applies 12 volts to the A/C low pressure switch signal circuit. The switch will open when the A/C low side pressure reaches 124 kPa (18 psi) . This prevents the A/C compressor from operating. The switch will then close when A/C low pressure side reaches 275 kPa (40 psi) . This enables the A/C compressor to turn back ON.