I drove it today and turned it off. Then I went to start back up and nothing. The key will not crank the engine. I can jump the solenoid and the starter works well but no spark either. The ignition key is not sending power to the solenoid. There are no dash lights, R N D. The only thing that works with key on is the headlights. Any ideas on what to check next?

 

On the 6 pole switch connector check that voltage is transmitted to the white/red wire when the 3 position switch is in the start position.This wire leads direct to the solenoid.If it's not, a simple ignition switch replacement may be all that's needed. If the wire is powering up,then could be a solenoid problem.

 

I replaced key switch and battery. There is 12v on the red wire to the key switch but only .004 volts out to solenoid when in start position. I noticed to there is 12v on both red wires into the voltage regulator but only the same .004 volts on the r/w wire out to the cdi. Could this be a bad voltage regulator. Also no dash lights and will not crank with just the .004 volts out to solenoid.

 

Sorry, not the voltage regulator but the ecm. It has 12 volts on 2 red wires in but only .004 volts out on the r/w to the cdi.

 

Oh yeah,forgot about the blamed ecm module on the 2003 Trail Boss 330. It and the 2003 Magnum 330 were the first ones that came out with ecm modules and neither one was on the recall list that started with the 2004 models. More than likely another one has bit the dust as it controlled so many different functions. I have the 2003 330 manual and even on the wiring diagram it calls the ecm a "regulator and fan/hot light controller" Doesn't really go into detail on it.I'd hate to say order one,but really no good way to test them. And yes I had to replace them on the 330 also just like you when they lost power to the dash lights and ignition and a new ecm solved that..4010944 MODULE-ELECTRONIC CONTROL

 

Finally figured it out. Before I bought a $200 ecm I went checking the wires again. The wires going into the run/stop switch on the left side handlebar were either loose or there had been brake fluid leaking on it from the master cylinder. This made the machine think it was in the off position. Cleaned the brake fluid off, cleaned the connections and works good now. I am not totally convinced the run/stop switch is not going bad but will wait for it to completely break before buying one. Thanks for your help.

 

Saved your self some bucks. If it happens again at least you know to just replace the left control switch. No use trying to take one apart to try to clean things up. Springs and ball bearings will fly out everywhere.