I have a 2007 Polaris Sportsman 500 EFI that randomly would loose all electrical power until one day it had no power period. I spend many hours tracing wiring, checking ground wires and the kill switch.

I sent my ECM Control Module (4011517) to ModuleMaster in Moscow ID to see if they could find the problem.

They found a few solder joints were broken and a surface mounted component that was bad. They re-soldered the pins and replaced the bad component and got power to all output pins on the connectors.

They shipped it back. I installed it, with battery disconnected. Then, connected the battery leads, black ground last.

Put the key in and it started right up. FIXED. And, the best part is the cost of the repair was about 1/3 the cost of a new one.

I am going to install battery disconnects, because the ECM stays powered up from the battery. Hopefully, this will prevent the ECM from failing again.

Rather than give Polaris $500 for a new ECM, call ModuleMaster first. Maybe they can fix yours too. They have a web site too, www.modulemaster.com