The clutch plate is the disc on the end of the compressor pulley.
When not engaged, the clutch is stationary whilst the main pulley still turns with the engine.
When engaged, the clutch plate is pulled in by an electromagnet and turns with the pulley.
The compressor then works to provide ac.
At this time of year, you should see the evaporator temperature reduce to around 6°C then the clutch will disengage, evaporator temperature will rise towards 10°C, the clutch engages, evaporator temp drops and the cycle continues ad infinitum.
