The two example wiring diagrams show how the diode is placed and where the +12CF-52GGNBX2B should be connected to the relay. The diode should be placed as close as possible to the device that produces back EMF when de-energized. The diode's Cathode (stripped side of the diode) is connected to the +12V that powers the compressor. The diodes Anode should be connected to your compressors housing (Ground). One example shows an ISO Standard Mini A/C Compressor Relay. The Normally Open (Pin 87) is the switched +12V that powers the compressor. The second example shows an ISO Micro A/C compressor relay. The Normally Open (Pin 5) is the switched +12V that powers the compressor.