I have a 08 Sportsman 500 efi. I bought it new, and it has been taken good care of. Used but not abused. Was riding a couple of days ago, just slow idle riding most of the time, had my 3 yr old with me, and was watching my 10 yr old ride in a hay field and some little trails. Was hot out (TX in July...) but nothing that should have hurt anything. The HOT warning started flashing on the speedo... started running rough. The fan was not running. I shut if off and let it cool a few minutes, then started it and rode to the house.

Have checked all I can find and searched here, but not gotten answers. NEED HELP please.

The fan is good. I unplugged it and put 12v to it, and it runs fine. No leaks and coolant is full. I do not see a them sensor on the radiator like some older units?


What are your thoughts? If the temp sensor is bad, where is it located and is there a replacement for it like a lot of the older models, from local autoparts store? Other things that could be causing it?

Thanks in advance!
Ken

 

Wash the radiator out real good, from both sides, take the front box off so yoe can get to the radiator cap and make sure its full, temp sensor is in the lower right corner, if you unplug it the fan should come on, if not its bad

 

if you unhook the fan w/ the key on it should have started running. maybe a bad sensor?

 

I don't think you have to remove the front box to access the rad cap . I have a 08 also just open the front box lid and remove the small rubber cover you cap in under it no tools required .

 

Thanks for the help, but still no fan. I have checked the fluid and Spdecat is correct on the 2008. Just open box and pull plug. Fluid is full and clean. Also, radiator is clean... I just do not have a fan. Riding at mid-speed, radiator gets air, and all is good. Sitting at idle, low speed, gets hot.

I can not find a sensor on the radiator. I have taken covers off, etc and there is no sensor on the radiator...

I did pull one sensor plug on left side of motor off, on cylinder right below the coolant line, and that did not do anything while at idle...

Again, this is a 2008 EFI 500. The fan works if I put 12 volts to it, at the plug connection. There has to be a sensor somewhere telling the fan to come on... I just can not find it.

Is there a parts site that gives schematics for each year?

OPT, where are you?

thanks again all!
Ken

 

Go to cheapcycleparts.com or bikebandits.com for schematics...go parkshark.com and go to downloads and you should be able to download a free service manual for your quad.

 

OK, thanks to the links from Mud Slinger, I have found the sensor, was on the cylinder like I thought, and also downloaded a manual. It says the sensor reduces resistance as temp goes up. Also says if it fails, it turns fan ON...

Sensor is to be at about 38 ohms at 68F per the manual and tonight at about 98F (gotta love TX heat) i was reading about 20.5 ohms... that says sensor is working. I will run the motor and get it hot tomorrow night.

I am still not understanding why the fan is not running. I am going to start tracing the wiring for the fan, and see where the wires trigger from the sensor to the fan. Will also try unplugging the sensor plug and shorting wires, and see what it does to fan... no resistance should turn the fan on...

Any other ideas here?

thanks,
Ken

 

I got this out of my Polaris manual . The relays next to the ECU assist with component operation such as the fan , fuel pump , etc . The fan relay , controlled by the ECU , operates the fan . So it could be a relay or your ECU .

 

The newer 500 have no fan switch in the rad, its screws in the side of the cylinder Part #12.

 

OK everyone, thought it might be the sensor, but...
No such luck. Sensor is working. I put a meter on it, and it is dropping resistance as it should as it heats up. Also, fan is not coming on when the sensor is unplugged, as the manual states. I also tried jumping the wires from the sensor to give 0 resistance, while motor was running, and still no fan.

I pulled front cover off, and saw the three relays, but not sure which is for fan. Also, on the wires running to the fan down under, looks like a relay taped to the power supply wires running to the plug on the fan, before it gets to the plug.

What is the plug pattern for the relays? I can test them, if I know what the plug order is.

Going to have to take more stuff apart to get to all the wires... big hands just dont fit in there well.

Any other ideas or direction here?