how do i tell if my fan clutch is working correctly?

Two ways. If your engine is not overheating during hot weather, it's probably okay. Second, when it's really hot outside, you should hear it's roar when the clutch engages. Also, it should be quiet when everything is cool and the clutch is disengaged. Sometimes mine will "roar" when it's cold, but that's just temporary. Noboby has been able to explain why this is so.

'nuff said?

Start the engine and let it warm up. If the temperature climbs beyond a certain point and the fan clutch doesn't kick in and start the fan, then you have a problem. Most of the time, the problem is either the thermostat that controls the fan clutch or the clutch itself.