First: I am aware of of the Polaris ECM recall.
So I accepted a 2004 Sportsman 400 that was rolled. I had a good frame from another sportsman that had a bad motor. I removed everything from the 2004 and relocated it to the new frame. Problem happened when I connected the battery. I had not realized that the positive lead for the hand warmers was touching the frame, as I had not connected them yet. This positive terminal was spliced into a 12v source going from/to the ignition switch and the ECM. I smell burning, remove the ground off the battery and notice the hand warmer lead being pressed onto a bolt by the wiring harness. Needless to say, this was a BAD short, but no melted wires ��I opened up my ECM .... she is fried. I taped up the positive lead for the hand warmers, TRIPLE checked all connections, opened up some wiring loom to ensure nothing was abnormal, checked polarity, voltage, grounds, cranking amps of the battery, and swapped ignition switch. I spent over an hour making sure there were no other problems. Everything looked great. No water, no corrosion, no burnt wires, you get the idea. I installed the other (and last) ECM i had and to my horror, ECM #2 gives up the smoke within seconds... it's as if I were installing the battery leads backwards or had a 24v batter installed. at this point i was furious and sleep deprived at 1:30 am. I removed the entire wiring harness, opened up all of the loom, and carefully inspected EVERY SINGLE WIRE AND CONNECTOR. However I found no problems at all. I am a master automotive and diesel technician, and this simple... toy, had me tossing and turning all night wondering what went wrong. At this point I am going to use the other wiring harness that I have, buy a new ECM, and go from there. I am going to assume that the harness was damaged somehow in the rollover (which wasn't that bad) and that I could not detect the problem when I inspected it. My question to you experts is: is it possible that this short that occurred, could have damaged another component that caused the second ECM to burn up? like the CDI box or ignition coil? Do you have ANY ideas, suggestions, or thoughts for me before dropping in a $150 ECM and potentially destroying that one as well? Thank you.
PS OLD POLARIS TECH! Help!! Your reputation has brought me here.
PSS does anyone have a wiring diagram for this thing?

 

 

I'd say use the other wiring harness and get another ecm. That's the logical thing at this point. These toys can confound and confuse the best mechanics at times. I had a couple techs from a near by Chevy dealership that came to me often whenever they had a problem child they couldn't figure out. If you'd feel better on doing some electrical component checks before you take the plunge on more parts, here's the manual for 5 bucks that has some good trouble shooting tests along with wiring schematic that can help.2004 Polaris Sportsman 400 Service Manual PDF Download Ecm modules control so many things. From controlling battery charging to cooling fan operation,battery protection circuits,accessory power,hot light along with all the circuit breakers in one module. Too many imo.

 

Thanks for the assurance, I'm feeling pretty defeated right now. But FYI I was able to find that manual for free. I could have had access to one for free at my local Polaris dealership, but its easier to print it from home.

Polaris Offroad Vehicle User Manuals Download - ManualsLib

 

Good to find a link for free manuals. They're getting few and far between now. Keep us updated as to your progress..