Hi Guys, hope everyone is doing well.

I recently noticed that my XT's fan kicks in when the bike already seems too hot, as the water started pushing out at the radiator cap...and the fan still did not kick in. The temperature light did not go on, but it does glow when i turn on the ignition. Ive checked the fan motor by connecting it straight on 12V, and it works fine. I then checked the switch that goes into the motor, im not sure what you call it, but i guess its something like a temperature/fan switch. I took this switch out and put in into warm water...and then realised that i dont know what it should actually do when it is warm/boiling water, and how to test if its working fine or not.

Can someone perhaps advise me as to how i can test this switch, or is there something else i should look at? O yes, and the fan's fuse a the battery is fine.

Thanks a lot
Schalk

The fan kicks in quite late.
At arround 90 C oil temperature and / or 115 C water temperature.
Therefore, testing the thermo sensor is difficult with boiling water (~ 100C).

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Saludos,
Joe
http://web538.ypsilon.ibone.ch/index...d=89&Itemid=42

neoprene fork protectors Acerbis / blue Puig wind shield / fork spacers 24mm / snorkel and resonater out / Acerbis hand protectors / 25 mm bar risers / 12 V outlet / "soft throttel mod" / engine protector home made / PC III USB / DNA ST2 / K&N ST 1 / BSM "Future extreme" exhaust / Wilbers "Adjustline" Shock / XTX links / luggage carrier home made / automatic chain oiler home made

During my testing, I discovered the fan on my bike (XTX) turns on at around 105C as I watched the temperature reading increase on my PCV software.

The 'switch' you pulled out, where did it come from?

Was is on the right side of the bike, same sort of height as the TPS on the back side of the cylinder and made of brass?

http://4.bp.blogspot.com/_vE1-EGFNds...660+Engine.jpg

At the top of that pic, in the middle.

If its what im thinking of its the temperature sensor.
As it heats up, the voltage across it drops so what you can do it put a multimeter across the 2 pins on it and measure the resistance.

It should be around the 2000 ohms mark at 20C and about 180 ohms at 100C

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09 XT660X:

CCC Stainless Rounds, Stage 1 DNA, Stage 2 DNA, PCV With Custom Autotune Map, PCV AutoTune, Home made O2 eliminator, Self machined Fork Spacers, DIY Autotune Switch.

Yes thats the switch i was referring to. :-)

Thank you very much for the feedback, its much appreciated, i'll measure the resistance as soon as possible.

Cheers
Schalk

If its your fan unit that is gone Kev just posted two links to fan units on the ebay section at the bottom. My fan unit broke about 2 weeks ago but i finally got one from germany.

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Plough on

Think his fan is fine so he says, tested it on a 12v source.

How old's the bike? How many miles?

I'm thinking about the radiator cap itself, whether thats faulty.
They're designed to be able to handle a certain pressure, thats how the coolant is allowed to go above 100c without boiling because its kept under pressure.

If the cap is faulty or doesn't produce a seal well, it may leak and boil over.

Might be worth having a look at the radiator cap, checking the condition of the seal and sealing faces.

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09 XT660X:

CCC Stainless Rounds, Stage 1 DNA, Stage 2 DNA, PCV With Custom Autotune Map, PCV AutoTune, Home made O2 eliminator, Self machined Fork Spacers, DIY Autotune Switch.