I have 1999 honda cbr 600 F4, I didn't know that I have the fan on my radiator, it's so hot down in florida. How do i know if the fan is working? I don't have the cool tach that some people have where it'll tell you the exact tempature number while mine just the picture. it does get pass half way and yet the fan didn't come on, it's plugged in and the fuses are good. WHat are the problem? Does it have to get way hotter like close to the red zone in order for the fan to turn on?

 

Half way is pretty much the normal range. That said if it hovers at half while riding you should hear the fan kick on while sitting for any length of time....such as at a light. As far as why it not coming on I'd have to look at the wiring diagram for possible causes but I'm at work. Good luck, if you can't figure it out shoot me a message and ill look into it more

 

I still can't figure it out

 

As long as your not getting into the upper third or quarter of your temp gauge then I'd have to assume its working. Warm it up to normal temp and then let it idle for a while. Watch the temp gauge and listen for the fan, it should kick on once the temp gets a little past halfway. If it goes into the top quarter or so and approaches the red, then I'd say you have some problems.

I'd check all your connections first, make sure they're all plugged in, and go from there.

 

I believe the exact temp the fan starts is 245 degrees F. You'll probly never be able to tell if it's on when your riding but let it sit while it's running after you've rode for a while and if it's not on by up 3/4 the way up to the top of the gauge there might be something wrong. You can here it and see it when it comes on, it's very small on the left side of the bike visible through the slot on the fairing. Not 100% sure but I believe that there are 2 separate Thermocouples, 1 for the gauge and one for the cpu to control the fan.