I've been having this weird issue lately where my bike is starting on its own as soon as I flip the switch into the run position (with key on). I don't need to press the start button, it just starts immediately after flipping to run.

When I pull the clutch in, you can hear a pretty bad grinding sound coming from the starter area, definitely like the bike is still trying to start itself (even after the 'auto start') ... but it only makes that sound when you pull the clutch all the way in.

It doesn't make the sound at all if the clutch is out and I'm riding...but if in neutral (clutch out, stopped) or clutch in the sound is there.

When you shut the bike off, the starter makes a really weird, electronic 'winding down' sound.

I've done a lot of research on this and did the following things:
- cleaned the fuse box with contact cleaner
- replaced both system relay and starter relay with new ones
- checked start button/run switch for bad/crimped cabling. Everything is clean all the way through...

When I rode it home the other day, the red battery light and check engine light on speedo came on. Did some more research and a lot of people suggested swapping the battery out with a new one. Did that...no luck.

I've seen some other posts suggesting to look at the starter soledoid, but i honestly don't know much about it or where to even locate it.

Any thoughts or clues out there? ANY suggestions you guys might have would be 100% appreciated, i wanna go for a rip horribly

ps, bike is a Nightster1200N. Thanks...

 

might have to pull the starter right off the bike to diagnose it properly, could be the gear over running in the nose cone and never disengaging.

EDIT: Scratch that, take a meter and see if the solenoid wire has power (Pos 12vdc) on it but disconnect the wire from the solenoid first. If it does then you have to trace backwards to see where it is getting it from.
Have the key on and the run switch on when testing.

 

If you can't locate the solenoid thats right on the starter you need a factory manual or maybe take it to someone that can do a little show and tell educating

 

http://partsfinder.onlinemicrofiche....=13&A=537&B=15
never know.
try this link for a blow up of the starter, may not make it any more clear but

 

Careful, it may start riding itself soon....

http://www.youtube.com/watch?v=Mo8Qls0HnWo

...that doesn't help you at all but I couldn't resist. Good luck with the repair!

 

Did you test the start switch with a meter? I would first test the leads to check they are not always on.. the switch may feel ok but the contacts could still be bad

 

Sounds like a short in the starter or starter switch

 

Since it happens when you flip the switch to the run

 

Since it happens when you flip the switch to the run position, swap the two relays and try it, if it doesn't try to start on it's own, then replace the relay. If it does, you got something going on with your starter button. You may need to loosen the hand control and check the wires where they pass through the dimple in the bar.

 

I had a similar problem but with a faulty clutch switch but would be intermitted so they couldnt find it until a month passed gggrrrrrr, lots of folks have issues with the nighty, they have electricle issues, but id be interested to see what it is, the obvious is in the switch?but im a harley mechanic wannabee