In the 2 1/2 years I have owned my 2010 XT660Z I have never seen or heard the cooling fan come on. It has also never previously shown signs of overheating. Yesterday while stop-start driving in an urban area (an uncommon environment for my bike) in 25*C temps the red temperature warning light came on. I immediately pulled over and let the bike rest for 45 minutes. There was no steam or indication of the coolant boiling. When I restarted, the light was off and stayed off for the entire, open road, 100KMH, 70 KM spin home.

Last time I changed the coolant, about 2,500KMs ago I checked the thermostat and it was working as spec'd in the manual. I did not test the engine temperature sensor, although yesterday's incident would indicate to me that it is working. Is the issue likely to be a faulty fan, or fan relay? Can I check the fan by simply connecting it directly to a 12v power source? I'm not good at reading wiring schematics, where is the fan relay? Anything else I should be looking for?

Thanks as always, Rich.

Hi Rich. Firstly, I'd ask are you confident that since changing fluids you have no air in the system? ... and secondly, I'm certain that you can simply put 12v across the fan terminals after you unplug the fan and it should start. Have a look through this lot.

https://www.google.pt/search?q=xt660...obile&ie=UTF-8

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I have a lot of growing up to do. I realized that the other day inside my fort.

Good advice...you could always leave your bike running for a while and wait till the fan comes on..5-10 minutes maybe...

I'm pretty confident that there's no air in the system, I think it would've shown itself before now if there were. The coolant change was 2,500KMs ago. I'll check again though.

I was editing my post . Have a look through the google link above.

__________________
I have a lot of growing up to do. I realized that the other day inside my fort.

I have never seen or heard the fan come on Nickroc, not even when the bike was plastered in semi liquid turf and buried up to its rear axle in a bog last month. Under normal circumstances would one expect the fan to come on after 10 minutes of idling?

As Nikroc mentioned. . It should kick in aftet 10 mins at idle.

__________________
I have a lot of growing up to do. I realized that the other day inside my fort.

Mine does..wont hurt none to try.

When I changed the coolant a few months ago I flushed the system out a few times with tap water and ran the bike until the system opened and removed any crud/build up.

Turns out it was a pretty simple issue; the fan wasn't plugged in! The bummer part is that the female part of the fan plug is distorted, because it had fallen down beside the header pipes, and it will no longer mate with the male side. At least it works.

Thanks for your input.

Simple fix..always the best!!