hi guys my sportsman overheats because fan wont turn on. this atv is new to me, came with acreage. i direct wired fan and it works. i unplugged sensor below thermostat but fan didnt come on. not sure if its suppose to. even jumped the wires no fan came on. i keep reading about sensor on top of rad but i dont see such senor. anyone steer me in right direction? have photos? online service manual? its an efi if it matters. thanks for your help

 

The sensor on the cylinder is just for the hot light,fan won't come on when you unplug it on this model. Usually the main problem on fan not cycling on is a shorted out thermal sensor located at the bottom of the radiator sensor.You can follow the sensor wiring up to the connector,unplug it and check its resistance when cold,then heat the sensor up with a hair dryer. Resistance should drop.If not it needs to be replaced as it's the ground path for the fan.Also there is a circuit breaker in a plastic pouch under the front panel that's for the fan. It can corrode,not allowing the fan to operate also. Just slice the pouch open and check for corrosion on the terminals if you don't have power on each side of the pouch. It's cheap at any auto store if needed. Plus make sure the radiator is clean especially around the fan area.If blocked with dirt or mud,engine can overheat before the fan has a chance to kick on.Item #24 is the thermal fan sensor.Dirt Cheap Yamaha & Polaris OEM Parts & Accessories – Cycle Parts Warehouse

 

the problem i have is locating radiator sensor. where is it located? only wires i see by rad are for fan, front lights and some wiring by a cooler infront of rad on bumper side. but is a big plug doesnt look like sensor i googled pictures of. thank you for your response. rad is pretty clean, i have owned a honda rubicon since 05 so been round atvs just not a polaris! i was told to sell this polaris that its junk lol only 2000 miles on it though. i followed wires that powers fan, but just goes into a wireloom shared with front right light

 

Look on the left side of the radiator(drivers side) I believe that model had the sensor close to the middle of the radiator(or top) not the bottom right as the earlier models did. The parts break down link I listed kinda shows the general area it's in.Plus don't over look the circuit breaker under the front panel. Split the pouch if necessary to check out the terminals.Cheap to replace. If all else fails,this is your best friend on problems on this first efi model that Polaris introduced if you don't already have a service manual.http://polaris-atv.brssm.com/2004-Po...ce-Manual.html

 

strange that is same diagram i seen on polaris parts site, top left of my rad i have rad hose, bottom left other rad hose, bottom right drain plug and nothing else! not even anything looking sheared off or a plug or nothing stumped, maybe just put a switch on the fan. weird

 

i will take photos after i have a sleep. dont see a pouch or the item u attached, hopefully photos can clear this up, will buy that service manual too thanks alot for your help

 

Shows the same location on all the 2004 models whether efi or carb operated.Again this early parts list may be different than the actual location. If it's not on the left side,check on the bottom right hand side of the radiator for the sensor. If it's no help,best to spend the 5 bucks for the manual for this model.Well worth the money on trouble shooting,repairs and maintenance. It's hard to remember all the changes from 10 years back that Polaris made.Plus looking at the 2005 700/800 manual I have the sensor that triggers the fan is the one in the head,radiator sensor isn't used on these models!. It's not just for the hot light only. Pull the sensor harness and see if the fan comes on when the key is turned on. If it does,could be this sensor has shorted.

 

That's your best decision!

 

ok so I bought the manual from the link provided. It says if I unplug the sensor on cylinder head, the fan should run. But my fan doesnt. So it says it could be a bad fan (tested fan so I know it works), or check solid state relay. But of course in the section of manual I need photos there is none lol. Just has your normal black and white wiring diagram but that doesnt really show me much and frankly quite hard to read! Anyone know where this solid state relay would be for the fan. says there is both 4 pin and 6 pin relays. This model doesnt have a sensor on the rad like the older models did. Just the thermic sensor on cylinder head. But I dont think that is my problem since when disconnected its suppose to default to on for the fan, but still not coming on! thanks

 

Lets back track a little as you haven't said whether your model is a carb or efi system. I'm just assuming it was an efi. If not a fan problem itself still could be from a corroded circuit breaker under the front panel that's there for the fan. Has two of them,one is the main circuit breaker up from the battery.Item #2.Dirt Cheap Yamaha & Polaris OEM Parts & Accessories – Cycle Parts Warehouse