A/C Compressor Relay

Using an ohmmeter, ensure there is no continuity between terminals No. 1 and 3. Ensure there is continuity between terminals No. 2 and 4. See Fig 1 . While applying battery voltage to terminal No. 2 and grounding terminal No. 4, ensure there is continuity between terminals No. 1 and 3.

Fig 1: A/C Compressor Relay

Courtesy of MITSUBISHI MOTOR SALES OF AMERICA.