The A/C compressor control relay cycles the compressor ON and OFF by energizing and de-energizing the compressor clutch coil.

With the key turned to the ON position, battery voltage is supplied to the relay common contact and to 1 coil terminal. The PCM grounds the second coil terminal under the following conditions:

When the relay is energized, current passes through the relay contacts. This action energizes the compressor clutch coil.