Cooling Fan Relay(s)

1. Disconnect battery ground cable, the remove relay box cover and relay (RDI FAN).
2. Using an ohmmeter, ensure there is continuity between terminals 1 and 2.
3. Ensure there is continuity between terminals 3 and 4.
4. Ensure there is no continuity between terminals 1 and 4.
5. Apply voltage across terminals 1 and 2:
a. Ensure there is no continuity between terminals 3 and 4.
6. Reverse procedure to install.