Hello, I put a new battery in the 400 and now it says it's running hot and the fan wont run. the fan is good because if i unplug it it will run off of a battery. Even after it sets there and becomes cold you can turn the key on and it flashes hot. It seems like this happened when it was under warranty and they had to replace some sort of electronic component.

 

Sounds like the temp sensor is faulty if it shows hot even when the engine is cold. Since fan shows ok when hooked up direct,I would suspect the sensor itself.Item #2. Shows $64 here. Dirt Cheap Yamaha & Polaris OEM Parts & Accessories – Cycle Parts Warehouse But can get it for $44 on ebay.http://www.ebay.com/itm/Polaris-Sportsman-400-500-Hot-Light-Thermo-Temp-Switch-3085352-/160993723755?pt=Motors_ATV_Parts_Accessories&hash=item257bf9456b&vxp=mtr Plus you may be able to match it up cheaper at a local auto store. IF the fan doesn't kick on at all when hooked up to the harness,could also even be the radiator sensor.Item #21.Dirt Cheap Yamaha & Polaris OEM Parts & Accessories – Cycle Parts Warehouse even these can be substituted by an after marker sensor like Wells#526 and just splice in your connector.Wells Vehicle Electronics Cooling Fan Switch SW526: Advance Auto Parts

 

Thank you "OLD POLARIS TECH"! I will check both switches tonight when i get home from work. If both switches check out good would you think it might be the ECM? I will let you know tomorow.
Thanks again for helping, I appreciate it

 

If you have the AQ model 400 with the ecm module and not the AA,the one with the regulator, then YES,I'd check into the ecm as this one changes also to the newer US made module! All the Chinese ecms are junk including ones like yours that weren't on the recall.Controls charging,fan,battery protection,hot light,etc! Item #30. Dirt Cheap Yamaha & Polaris OEM Parts & Accessories – Cycle Parts Warehouse http://www.ebay.com/itm/2004-2006-Polaris-Sportsman-and-Scrambler-400-450-500-OEM-Surepower-ECM-2005-PDM-/171576768506?pt=Motors_ATV_Parts_Accessories&fits=Make%3APolaris&hash=item27f2c5b7fa&vxp=mtr

 

Yes Sir, it's the AQ and I will let you know. I have been using cyclepartswarehouse for a while.

 

It was the ECM, thanks Mr. Polaris Tech. you have helped me again

 

I'm not a Mr. I'm an Old Polaris Tech.. Hope it's doing ok now.