Can someone tell me where I would find the temperature sensor (or sending unit) on this engine? This would be the sensor that turns the electric fan on and off. Recently my fan quit coming on and ordinarily if I work it hard or drive around slow, the fan would come on. I asked the dealer about it and he said "Ahh don't worry about it - it's not hot enough out for the fan to come on".

Anyways - can someone give me a clue where to find this item on the engine?

Thanks so much!

Chris

 

number 7 in this view Back side of the motor, and it looks to be a spendy item.
Theres a procedure for trouble shooting this.
If you disconnect the two pin connector, from the cooling fan control unit( under the front fenders). There will be a light blue wire, ...between it and ground, you should get 9.5k to 10.5k ohms. This is on a cold motor. As the motor warms up, the resistance falls.
If its not in that ohm range, then check your wires for being disconnected or broken.
There are specs for testing the sensor in a pan of hot oil, let me know if you want those specs.
Theres another thing you could do ...you can wire the fan so it will come on by a toggle switch AND still have it come on when the sensor tells it to.
Theres also a 4 pin connector on the cooling fan control unit, and theres a dark blue wire in that 4 pin connector. Get an inline fuse, run from the 12 volt positive , thru a switch, and hook it up to that dark blue wire. Anytime you want the fan on, flip the switch, ...if you forget about the switch and the motor gets hot, it still will come on by the thermocouple switch too.
welcome to the forums.

 

Thanks for the info - any additional specs would be great.
One more question - when you say back of engine, do you truly mean the back as in towards the rear of the quad?

 

Yep, back under the rope pull.

Using an ohmmeter and alligator clips,one to the lead and one to the houseing, suspend the sensor in motor oil. Make sure the one lead on the sensor isnt touching the metal of the pot or itll give false ohm readings. Using a thermometer, at 302 F,it should have 306 to 340 ohms, at 338 F, it should have 209 to 231 ohms.
First thing i would check, is see if the wire came off the sensor.
Oh ya, be careful, thats awfully hot oil. Let us know what you find.

 

Well - I found the sensor (thanks for your help). I ended up just replacing the sensor with a new one ( I had already purchased it) and now the fan works when it is supposed to.

THanks for your help!

Chris

 

Thanks for the update.

 

Do I have to take the front fenders off to get at it

 

No, the sender unit is at the back of the engine near the pull start, you get at it from under the quad. Test the system by removing the wire from the sender and, with the ignition switched on, touch the wire against the engine. The fan should start up. If it doesn’t, the fault is the fan or the wiring, check the fuse first. If the fan does start and you are sure it was not coming on when the engine was hot enough to require it, change the sender unit.