Love my BF - NEVER a problem till last weekend.
Overheated coz fan wouldn't come on & stay on. It would start to spin - 2 seconds then stop. Then 3 seconds & Stop - does this 5-10 times then MAYBE will spin and stay on. Read up up the problem, called my mechanic (new fan is $400+ OUCH!!)
I ride a bike more often than the ATV so I'm hoping its corrosion from lack of use in the infamous Bus Connector - NYROC has a great write-up but it doesn't look ANYTHING like mine. Took the rear plastic off to try the fix but can't find it to clean it / splice it.
I think the article is for a IRS - I have SRA
Can anyone tell me where this is or give me a clue to the problem - I'm heading to Hatfield in 3 weeks and will need it there??
Thanks
JS
D'Oh!! its an '05 BF650 - sorry

 

You are right that tghe BUS connector mod is for IRS only (mainly 750), not for SRA BF. There is such connector on your quad.

There are 3 possible causes on your problem. One or more of the following parts can be bad.
1. Fan Circuit Breaker - Under the seat, easily damaged internally due to water/dust intrusion. You may try 10-amp fuse instead.
2. Fan Switch - On the left upper corner of the radiator, internal damage (broken temp sensor inside, very brittle like glass). Do ohm test and using hot water.
3. Fan motor - Usually water damage internally but overheating can damage as well. Connect direct 12 VDC and test.

Work on above order to save $$. Good luck.

 

Hayashi
Thanks for the reply - I jumper'd the the wires to the sensor - fan came on right away with ignition off. so... I'm guessing its the sensor. If I test using multi-meter & hot H20 will it have different readings or will it be 'off or on' - can I just test continuity?
I appreciate the help.

Also....
the "Fan Circuit Breaker - Under the seat, easily damaged internally due to water/dust intrusion. You may try 10-amp fuse instead."
there are only 2 fuses in the block - acc and eng brake. is there something else that I am missing??
Thanks again
JS

 

The fan switch continuity must be checked by submerging the probe end into the boiling water. When cold, open. When hot, closed.

You are looking at the fuses, not the circuit breaker. It is right next to them, front of igniter. The fan motor CB is inside its own rubberish jacket. You are in the right area!

Good Luck!

 

Dude, You're a big help!!
Used continuity tester & Digi Thermometer in boiling Water. Sensor seems to be nothing but a switch - on or off. Worked in the pan so I cleaned the terminals and put it back together w/ Dielectric grease - works like a champ - fan on @ 200 - off @ 180. Cycled it 5 times - solid!

My problem was crud & crud is always cheaper than parts - Happy Me!!

Gotta LOVE forums with smart people willing to give their time & talent - makes the world go 'round!

(Now I just gotta fix my winch, change brakes, oil, filters, lube cables and I'll be ready to go!)

THANK YOU VERY MUCH!
JS

 

You are welcome.
One more happy quad rider - that's all I need to hear!

BTW, I like your screen name because I love those big shrimps! Yum, Yum!