Fan clutch engaging at random times

[jpt548]

So I have a 1990 ls400 and I have replaced my fan clutch yet still some times it just chooses to run at random times and won’t shut off even after the car has sat for more than 3 hours and therory’s?

[RX400h]

Have you checked the temperature sensor that switches power to the fan?

[Jeremy M.]

Just to clarify, are you talking about the fan clutch for your radiator fan? I was under the impression that all the LS400s had a hydraulic fan clutch that spins off a pulley and isn't electronically controlled.

If not that, are you talking about the smaller fan visible from the front of your radiator (the AC condenser fan) which is a black plastic electric fan?