Reply to "Radiator Fan Relay Out?"

If the relay clicks and the light comes on, then the relay (for that fan) should be working as the light wire is connected to the same relay output terminal as the fan. Check for voltage at the fan positive terminal (wire) to ground (not the fan housing). If ok, then you probably have a bad fan or a bad ground. You will need to jumper the fan thermostat for this test.

You can also connect a jumper wire from the fan positive terminal to the battery positive terminal to check the fan.

Check the color of the positive wire on each fan and find those colors at the fan relays. The colors will vary depending on year and what happened to be within reach at the factory. They will probably be blue and yellow or blue and gray. Jumper the thermostat(s) wires and measure the voltage at the relay output terminals. You could have a bad fan thermostat.

Keep in mind that a voltmeter is a very small load and can show voltage present at a wire or terminal, but when a large load is applied, that voltage reading could go to zero if there is a bad connection somewhere (or bad relay contacts) upstream of the measuring point.

John