z400 fan help

[rdstoner]

my buddy has a z400 and he doesnt know how the fan knows to turn on? is it just on a timer or is there a sensor that tells it when to turn on. he thinks that it is over heating when he rides because it turns on while he is rideing any help would be good.

[ifixtheyride]

It's normal for the fan to come on and off during riding it is driven by a thermal switch located in your radiator one is for the idiot light and the other for the fan. They are normally closed switches I believe and when they reach a certain temperature they complete the circuit allowing the fan to come on and coolthe motor to safe levels same as a car.