Switchback 600 died on the trail, no spark now.

[sitdwnandhngon]

I have a 2010 Switchback 600. We went out riding this afternoon. It was running great for a few hours, no issues at all.

I hit a few small jumps and got back on the trail and as soon as I slowed down to corner it died like I hit the kill switch. I tried cycling the kill switch and the key on and off a few times and we pulled a plug out to check for spark and I'm not getting any spark that we could see on the trail.

The only indication something may have been off that it gave me prior to that was a hesitation when getting on the throttle at about 6000rpm, not long after that is when it died on me.

Ended up getting towed out and trailered it back to the shop.

I'm just wondering where I should start looking to diagnose the problem, or if there was any problems that may have been common like that with those sleds.

I appreciate any ideas or help, thanks.

 

[05rmksteve]

By pass kill switch and throttle safety switch and check for spark. Also those sleds where known for the voltage regulator to go bad.

 

[sitdwnandhngon]

Thanks. I did a quick test by just unplugging the kill switch and key assembly, but nothing happened. I wasn't sure if I was supposed to jump some wires or if just unplugging them will do the trick.

I'm going to dive into it tomorrow morning and try to check the wiring harness out.

I did recently test the throttle safety switch using the method described in the manual, and that worked fine, so I don't think that was in.

Is there any way to test the voltage regulator or do I just need to order a new one as part of the diagnosing process?

 

[sitdwnandhngon]

Wanted to come back with an update.

It's up and running again, but I'm not 100% sure what the issue was, had to have been a safety switch plug connection, because I had no spark this morning after sitting in the warm shop all night.

I took the airbox out and went right through the harness and took all the plugs apart (including the big cluster on the ECU) except the ones coming from the stator and the fuel system.

I pulled it over with everything apart and got a strong spark, so I wiggled everything back together tight and it fired right up.

I did take the flywheel cover off, and one of the bolts was buggered up, the stator looked good so I'm guessing it had been changed in the past, and the voltage regulator also looked much cleaner than everything around it.

I did learn a trail hack for next time though. If you unplug the big cluster from the ECU it disables all the switches and aux electric and the sled will start and run. Had I known that yesterday I could have limped it back to the trailhead instead of getting towed.

I'm just gonna keep running it and hope it doesn't happen again, but I know we can tow it out or hotwire it now as long as the ignition system doesn't fail.

 

[sitdwnandhngon]

Had to come back again.

Did a few rides last week with no problem.

Went to load it on the trailer today....no spark. Fiddled with the connections again, cleaned everything I could get to, and it started up. Did a loop around my lawn and it died with no spark again.

That was pretty much that and I can't get it to give me a spark again, I've cleaned all the connectors several times, and now I'm thinking it may be the ECU, even though it doesn't show any signs of damage underneath.

Should I got to the sled salvage place and grab one to test it out or is there anything else I should look at first?

 

[05rmksteve]

Sounds like the voltage regulator is bad.

 

[sitdwnandhngon]

Would the voltage regulator give me a no spark condition?

I thought maybe it was the pins in the harness so I just spent some time carefully cleaning them all with a small wire, I got a little bit of corrosion out, but not much. Didn't change anything.

 

[05rmksteve]

Yes a failing voltage regulator can cause all kinds of issues, no spark, no lights, gauge cluster not working and can also fry your ecu.

 

[sitdwnandhngon]

I'm going to load the sled up on the trailer this morning and head to the parts place with it. See if we can't swap out one thing at a time and see if we can isolate the issue.

 

[sitdwnandhngon]

Right after making the previous post I went out to the shop and decided to load test the capacitor.

It was sitting at zero so I hooked a 12v jump pack to it to load it. It read 14.5 volts after that and then I plugged it back in.

I had the ECU unplugged while doing this, but when I plugged it back in the connector sparked a bit and I heard it discharge. I plugged the ECU back in and pulled it and had a good strong spark. Put the plugs in and it fired right up.

Would this indicate a capacitor failure or voltage regulator? I'll change both just because, but I'm assuming that the voltage regulator was not properly charging the capacitor, or the capacitor wouldn't take a charge.

 

[sitdwnandhngon]

Another update. rmksteve was right, the voltage regulator was the culprit.

What I think happened was when I charge the capacitor, then it back fed into the VR, it kicked it back to life enough to get the sled running.

I put a used VR and capacitor on today before a ride, then did 150 miles with zero issues.

So I'm going to order a brand new VR and capacitor for the sled, and put the used ones right in my trail bag just incase.