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Discussion Starter #1
Hi, y'all. I got this 450r and the fan isn't working. In the past, on other machines, I've been able to test the thermo switch by putting in it hot water and testing the terminals for resistance. However, on this Honda, the thermo switch only has 1 terminal. So, I'm kinda puzzled on how this one works. The "old" style would "connect" the 2 terminals, therefore completing the circuit, when it got to a certain temp, right? I also wonder how I could test the fan motor without messing something up.

Thanks for any help.
 

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Unplug the fan and apply battery voltage to the motor terminals, motor will run either forward or backward depending on how connected - if you want to see it running the correct direction, connect + to the blue lead. Dark green is ground.

To test the sensor, connect one meter lead to the terminal and the other lead to the body of the sensor - suspend in water and heat the water - the resistance of the sensor will decrease as the unit heats.

To test to insure fan operation - start the engine and connect the sensor wire to ground, (the fan should run) - if the fan motor is good, but does not run with the sensor wire connected to ground while the engine is running, replace the condenser (acts as a battery). To observe the sensor operation; remove the sensor from the engine, plug the hole, fill the engine with distilled water or coolant, extend the sensor wire and connect it to the terminal, connect the sensors body with a wire to the engine (ground), start the engine, suspend the sensor in a pan of water and heat the water - just at the point the water starts to boil, the fan should come on - stopping the engine will stop the fan and removing the sensor from the hot water will stop the fan when the sensor cools.
 

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Discussion Starter #3
Unplug the fan and apply battery voltage to the motor terminals, motor will run either forward or backward depending on how connected - if you want to see it running the correct direction, connect + to the blue lead. Dark green is ground.

To test the sensor, connect one meter lead to the terminal and the other lead to the body of the sensor - suspend in water and heat the water - the resistance of the sensor will decrease as the unit heats.

To test to insure fan operation - start the engine and connect the sensor wire to ground, (the fan should run) - if the fan motor is good, but does not run with the sensor wire connected to ground while the engine is running, replace the condenser (acts as a battery). To observe the sensor operation; remove the sensor from the engine, plug the hole, fill the engine with distilled water or coolant, extend the sensor wire and connect it to the terminal, connect the sensors body with a wire to the engine (ground), start the engine, suspend the sensor in a pan of water and heat the water - just at the point the water starts to boil, the fan should come on - stopping the engine will stop the fan and removing the sensor from the hot water will stop the fan when the sensor cools.
Alrighty. Thank you. I'll try that here in a bit. :smile2:
 

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Discussion Starter #4
I tried the jumper wire on the etc connector, started the engine, and the light came on. So according to the manual the system is ok. I also applied 12 v to the wires that go to the fan and got nothing. The key shouldn't have to be on for that, right? I did it both key on and key off, so I guess it doesn't matter, Lol. So, it looks like I'm going to order a new fan motor. They aint cheap, so I wanna be sure!
 

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If you unplugged the fan and put 12 volts on the wires going to the fan then of course it would not make a difference if the key were on or not because the fan is disconnected from the wiring harness
 

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Discussion Starter #6
Wasn't the fan motor after all. While the new fan motor was on its way, I did more testing and found the old fan worked. So, I sent the motor back and ordered an etc thermo switch and that took care of the problem. $37 vs. $162! Now, onto the jetting/ bog situation.
 
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