Air Conditioning Clutch (A/C Clutch)

On factory installed A/C system, PCM receives signal voltage from A/C Clutch switch indication that the air conditioning compressor clutch is engaged. The PCM uses the A/C Clutch switch signal to adjust line pressure to compensate for additional engine load. If the A/C Clutch switch fails with closed contacts, line pressure will be slightly low with air conditioning off. If the A/C Clutch switch fails with open contacts, line pressure will be slightly higher with air conditioning on.