I've done a lot of searching but haven't really found what I'm looking for. I have a 2007 sportsman 500 efi. last week the battery light came on and wouldn't start without pulling it over. i charged the battery and after a few days it did the same thing. i put a volt meter on it and when running it wont go above 11.5 no matter what rpm. I'm not sure where to go from here. Thanks for any help

 

Charging is through the ecm module located at the front of the machine.The stator supplies the initial output,but this module did give us some problems,especially where it's located where water can get in and cause damage. Check that all the wiring connectors are plugged in,clean em if you can and see if it helps.If it doesn't charge around 14 volts back to the battery,then most likely this module needs to be replaced. Item #11.Dirt Cheap Yamaha, Honda, Arctic Cat & Polaris OEM Parts & Accessories – Cycle Parts Warehouse

 

Ok thanks Ill go check the connections. Hopefully that's all it is

 

I checked the connections and cleaned them the best i could but no change

 

You can check resistance on the three yellow stator wires between each other. Between y1 y2,y3 there should be around .043 ohms with no yellow shorting to ground. If the readings are within 20% then more than likely the ecm is at fault if the battery isn't charging

 

You can check resistance between the three yellow stator wires going to the ecm. Should be 0.43 ohm + or - 20 with no yellow shorting to ground. If this checks out more than likely the ecm is at fault.

 

Assuming i did everything right the stator checks out. So that just leaves the ecu, is there anyway to test the ecu itself? i hate to spend that kind of money and not be the problem.

 

Tests on charging show once you eliminate the stator as a possible problem then replace the ecm(pdm) module.No really good way in the manual to test this module as it controls charging,fan operation,plus does have a couple internal circuit breakers than can go out.Electrical gurus out there can probably pull the module apart and replace parts,but the average Joe can't.

 

how many volts should the stator put out? This is ac correct? I almost ordered a pdm today but i want to be 100% and the dealers i talked today were no help at all.

 

Pull the three yellow wires from the pdm module. Crank the engine and have at an idle. Measure VAC between y1 to y2,y1 to y3,y2 to y3. According to the manual ac voltage should be no less than 30 to 40 vac at 2000 rpms. If there is a significant difference between each "leg" then the stator could be at fault.