Test

A/C Thermo Switch

Dip A/C thermo switch into a pan filled with ice water, and check for continuity between the terminals.

Cut off: 1.5--0.5°C (35-33°F) Cut in: 2.5-5°C (36-41 °F)
If cut off or cut in temperature is too low or too high, replace the thermo switch.

Relay

NOTE: All A/C system relays are similar.

1. Check for continuity between terminals 1 and 3.
2. Connect a 12 V battery across terminals 2 and 4. There should be continuity between terminals 1 and 3 .