Cooling fan constantly on

[Starfighter]

When I start the bike cold the cooling fan goes on immediately and stays on during riding and does not shut off untill bike is turned off.

Bike was running pretty hot last week and I noticed the cooling expansion tank was empty. There was cooling liquid in the radiator tho. Added cooling liquid up to the lower marker and the heating seems to have subsided.

No warning lights at any point have come on. Im guessing a bad relay or temp sensor?

 

[Gregger]

When I start the bike cold the cooling fan goes on immediately and stays on during riding and does not shut off untill bike is turned off.

Bike was running pretty hot last week and I noticed the cooling expansion tank was empty. There was cooling liquid in the radiator tho. Added cooling liquid up to the lower marker and the heating seems to have subsided.

No warning lights at any point have come on. Im guessing a bad relay or temp sensor?

Yep...

 

[TURBO200R4]

I think relay first
If relays are hanging upside down they fill with water and short or get rusted.
If it still stays on then tuneecu can check what the temperature sensor is doing.
If you buy the 5 prong starter relay then that will replace any relay on the bike. Good for spares.
In Arizona it gets HOT so i wired a couple of wires that I can twist together and have the fan run even when the motor is not running so in an emergency i can have it cool off by just twisting the wires. Of coarse it sets a code with check engine light on .