Relays, Sensors and Switches

Blower Motor Relay

The blower motor relay is used to provide battery voltage to the blower motor only during high blower motor speed. The blower motor resistor is used to provide power to the blower motor in all other speed settings. The blower motor relay is located under the instrument panel.

Air Conditioning Compressor Relay

The air conditioning compressor relay is used to provide battery voltage to the compressor clutch coil. The relay is controlled by the powertrain control module (PCM) only. The relay is located in the underhood electrical center.

Air Conditioning Refrigerant Pressure Sensor

The A/C refrigerant pressure sensor attached to the air conditioning evaporator liquid line, senses refrigerant pressure on the air conditioning system high-side. The refrigerant pressure status is sent to the PCM. The purpose of this sensor is to inform the PCM of high-side pressure status so the PCM can:

^ Control cooling fan operation.
^ Prevent compressor operation if ambient temperatures are too cold.
^ Disable the compressor before high-side pressure becomes too high.
^ Diagnosis of compressor controls.