Trail Boss, Stoppe charging and cooling fan won't shut off
 

Just trie dto start the 05 Trail Boss yesterday. Battery was dead so I jumped it off the lawn mower. It started fine but as soon as I removed the cables it died. Let it run about 20 minutes and it would only run about 10 seconds with cable unhooked. I could hook it back up when it started sputtering and it would run fine. Also when i shut off my key the cooling fan contin ued to run with key off. Is this normal and is it possibly a bad cdi. Thanks Tony

Probably a bad ecm module since it controls charging and fan operation. Have the battery load tested if not sure about it,plus make sure battery connection are tight. Think the recall included the 330 but not shown on the expanded list(may be on the original list) Anyway IF you have a BLACK finned Chinese ecm module it needs to be changed and even if it has the replacement module,they can go out as I replaced multiple ecms on the same atvs along with posts from others that have done the same. OPT

If I remember this is different from my 03 in that it has a ecm and a cdi box. This one has a silver pure polaris surepower ecm on it.Would a bad battery contribute to this problem also. Should the fan kick off with the key or by temp regardless of key. Thanks OPT you are a valuable asset to this forum

The fan should NOT run with the key turned off.

Just charge the battery up and have it load tested at an auto store to see if you need a new one. Then crank up the machine and see if you're getting 14 volts back to the battery. If not then it's probably the ecm module even though it's the newer silver Shure power ecm. One sign of a bad ecm is when the fan continues to run with the ignition off! If you've narrowed it down to the ecm and not just a bad battery,replace it before any you possibly could have any wiring damage or even a fire! Disconnect the battery until you get the new ecm module. OPT

Bad ECM. Was covered but already replaced 5 years ago. Dirt cheap atv was the cheapest at 122.00 and free shipping. Thanks TonyT

STILL!!! Changed and put a new ECM on it from dirt cheap atv parts. Started up machine. turned it back off and fan is still running. Anything else? Bad part?

Not impossible to have a bad one straight out of the box(I've had a few),but sounds like you need to do some wire chasing too.The fan is controlled by the ecm,but trace the wiring coming out of the ecm harness (check the harness connectors also) and see if you can find a short. If all checks out then could be another bad ecm. Forgot!! Also check the sealed 10 amp fan thermal circuit breaker under the front panel and the wiring,could be problems there? OPT

I will check this weekend. They did send a new harness with it also. ECM to fan and 2 other plugs. Thanks

Got a message from the supplier to have it checked at a shop when it is off the bike. I called a shop and they said they don't have atester but does the fan continue to run. I told them yes and their answer was "it's bad". All wiring and connections look good. This just happened between runs. Last season no problems, this season problems. Supplier did say he would work it out so I guess I just wait and see. Do they make an ECM tester and do most shops have them. My local ones are pretty pricey. They wanted 900 to put in a silent chain. Hate to deal with them. thanks