Polaris ATV Forum banner

1 - 8 of 8 Posts

·
Registered
Joined
·
7 Posts
Discussion Starter #1
I've got a 2011 sportsman 800. Fan quit the other day. Ran 12V to check fan. Runs fine. Pulled plug off temp sensor. Fan did not start on its own as it should. Brought my buddies 800 over. Swapped out both relays, and ECM. My parts worked in his machine. His parts did not in mine. Coolant level is fine. Can't find any other broken wires or disconnected parts anywhere else. The only thing I haven't changed out is the temp sensor which seems to be working fine. Besides the fan should run when it is unplugged anyway.

Looking for suggestions other than just putting a switch in.
 

·
Registered
Joined
·
54 Posts
I've got a 2011 sportsman 800. Fan quit the other day. Ran 12V to check fan. Runs fine. Pulled plug off temp sensor. Fan did not start on its own as it should. Brought my buddies 800 over. Swapped out both relays, and ECM. My parts worked in his machine. His parts did not in mine. Coolant level is fine. Can't find any other broken wires or disconnected parts anywhere else. The only thing I haven't changed out is the temp sensor which seems to be working fine. Besides the fan should run when it is unplugged anyway.

Looking for suggestions other than just putting a switch in.
Are you sure it is supposed to come on if the temp sensor is unplugged?
 

·
Registered
Joined
·
417 Posts
If the metal overload is bad the fan won't run regardless. On the 550&850 it's under the front rack taped too the wiring harness by the fuse box. Not sure on the 800, maybe under the seat
 

·
Registered
Joined
·
255 Posts
Although my machine is an '08 500 Model T, I looked in my shop manual for possible ideas. The wiring diagram for the fan shows a 10 amp circuit breaker in the wiring between the buss bar and the relay with a red wire. Have you checked this circuit to ensure you are getting power through this breaker to the relay? That supplies the power to the fan when the relay is activated by the ECU. Note that I also checked my shop manual for my wife's '12 550 and the circuit layout is the same except that the HOT from the circuit breaker comes in to the relay on a RD/WH wire. You also need to ensure you have battery power coming to the relay which is used to activate the relay to close the circuit to the fan by grounding thru the ECU.
 

·
Registered
Joined
·
417 Posts
The engine coolant temperature sensor measures coolant temperature. The engine temperature sensor is a Negative Temperature Coefficient (NTC) type sensor, as the temperature increases the resistance decreases.
Coolant passes through the cylinder and by the sensor probe, varying a resistance reading which is relayed to the ECU. This signal is processed by the ECU and compared to its programming for determining the fuel and ignition requirements during operation. The ECU also uses this signal to determine when to activate the fan during operation.
ECT Sensor Test
To quickly rule out other components and wiring related to the ECT, disconnect the harness from the ECT sensor and start the engine. After a few seconds, the fan should turn on and the “Over Temp” indicator should display on the instrument cluster. This indicates all other components are working properly.

ECT Sensor Resistance Readings

Temperature °F (°C)
Resistance
32 °F (0 °C)
5.9kΩ± 5%
68 °F (20 °C)
2.5kΩ± 5%
176 °F (80 °C)
323Ω± 5%
212 °F (100 °C)
186Ω± 5%
 

·
Registered
Joined
·
7 Posts
Discussion Starter #7
Thanks guys. Turns out it was that circuit breaker. Not the breaker itself, but the pos terminal it connected to was broke. I had been lookin for that n couldn't find it. Shortly after posting I found it, and after a few mods and relocations. Got it up n running again. Thanks again
 
1 - 8 of 8 Posts
Top