Hi all, hoping someone here can lend a hand. I have a trailboss330 2005. Problems started a couple of months ago. Turn the ignition switch to on & the dash flashes the hot warning (the fan is't running) and I cannot start the quad. By feeding the starter motor direct from the battery it will start although the hot warning is still there. If I turn the ignition on & the warning isn't there it will start fine but the warning may come on whilst riding. A new thermistor has made no difference. I have never got to the bottom of this. Haven't used it since before Xmas. Now I turn the ignition on I have noticed the hot indicator flashing but have no headlights, horn, brake lights, indicators working, even when I turn the ignition and the hot isn't flashing I still have no ancillarys & can't start the quad in the correct way. Presumably because it's not receiving a signal via the brake switches. (Not certain if this was happening originally though) I have the 2 ecu / ecm set up on this quad, I have scoured the official Polaris manual & found the wiring diagram although it doesn't show the 2nd auxilliary ecu in the diagram and the wiring from the main ecu plug is very slightly different. It does reference it later in the chapter and i have an understanding of what it's doing. Also there is no illumination to the dash bulbs (neutral, reverse etc) but these are working on the main clock assembly so that would say the transmission switch is ok. All my tests are pointing towards both of the ecu boxes being faulty for different reasons & needless to say expensive parts, but my knowledge of these quads is limited & I'm hoping some of you guys can help me out. Thanks in advance, Brian

 

Its not on the recall list ATV: Polaris Ind. expands recall of ATVs but in 2004,2005 and 2006 Polaris where using some cheap A$# ECM units.

I take it, it was not really over heating since it's a AIR/Oil cooled motor and the fan is just for assist feature for the oil cooler. More of a false alarm warning light.

My 350 Big Bear was Air/Oil with a oil cooler as well and did not even come with a fan assist option.

 

No, it's not overheating, like it from cold not having run. More like some kind of failed circuit. Trying to ascertain whether it's one or both of these ecu boxes at fault (the made in China stamp doesn't give me confidence) or maybe someone else out there has had some kind of wiring fault that causes this? Thanks

 

Even if the Chinese ecm has been replaced before, the US made Surpower modules can fail.I've replaced several on the 330 and yes they weren't on the recall list but should have been. Controls charging,fan,plus has several internal circuit breakers that can short out. Replace it before anything major happens. This is the updated one for your model.http://www.ebay.com/itm/OEM-Polaris-Superpower-ECM-Kit-2005-2006-Trail-Boss-Magnum-330-/141003802233?pt=Motors_ATV_Parts_Accessories&hash=item20d47b4679&vxp=mtr Plus here's one that shorted out.

 

Guessing the wiring included with this unit is to fit direct to my loom, does this then link to the second ecu as I noticed the on the wiring diagram that the wires At the blue plug are slightly different to mine on the quad & the diagram doesn't show the second ecu. Would the fan ecu being broken affect the auxiliary ecu functioning or could there be a fault elsewhere affecting both of these units? Whole system seems very over engineered just to control charging, lighting etc especially if they're as unreliable as what I'm reading. I'm starting to think I'm going to end up having to buy both these units just to see if it cures the problem?

 

The new ecm simply replaces the old black Chinese module you have now. The harness jumpers that fit the new modules are made to fit your existing harness connectors. Instructions are included with the kit.Very simple to replace.