Okay. So I'm not sure how weird this sounds but I'm having a major issue with my 2009 nightster. Basically I turn the key to the on position, turn the bikes switch to run and without pressing the actual start button the bike starts itself after a few seconds if it's cold or immediately if it's warm. The bike will not start with the run button nor can you actually cycle the starter with it once the bike is on. After the bike starts up it cycles the starter for a few seconds. When you pull the clutch all the way down to put the bike into gear the starter cycles again. If you barely pull it in, the clutch wont engage the starter and you can still change gears. The starter cycles every time the clutch is pulled in.

I've taken apart the handle bars to look for a clamped wire and i've run down most the bike(Taking off the seat and gas tank, along with the battery cover) to see if there are any exposed wires rubbing on one another but have found nothing. I'm at a bit of a loss. Any Help would be much appreciated.

 

Are there any mods to your bike, such as internal handlebar wiring, or extended wires for apes, anything like that? Consider asking this in the Sporty section, where more members will see your query.

 

Yup, sound like the wiring to the starter solenoid is shorting. Or possibly the switch itself is bad.

 

My guess would be that it is a bad starter relay stuck on. I think your bike has to have the clutch in for the ecm to relay that signal to starter to engage?

 

Had the something similar happen to my 09 Road King, dealer replaced many things and it wasn't until it would stop trying to start itself and I had to pull the wire to get it to a dealer that they found the switch on the handlebar to be defective.


My symptoms were as soon as you turned the ignition switch on the bike would start as if I was hitting the start/run switch. You could also hear the starter engage sometimes when the bike was already running. It did not do it all the time which is why it took the dealer so long to diagnosis.

 

It does not sound like a stuck starter relay.

If the start relay sticks in the on position, the starter will crank as soon as the ignition is turned on, and it will not stop cranking until the ignition switch is turned off (on this model bike).

Symptom (without pushing the start button):

Turn on ignition switch and kill switch.

If the transmission is in neutral, the starter will crank.

If the transmission is in gear, starter will not crank, but pulling in the clutch lever causes the starter to crank.

This means...

Everything is working correctly....except the starter switch, it is sticking in the on position.

 

Disconnect the right controls and see if it stops?
Check for current on pin 86 of the relay?
Dan, anyone do you know how the safety switches are wired, trans, clutch then start switch?
Or is it controlled by the bcm, if there is one on the sportster?

 

I appreciate all the help, I'll try the stuff that's been listed and get back you guys soon. thanks again.

 

Does it start with the kill switch off?
If so it is the relay. The kill switch feeds the start, at least it did before bcm's.
If not it is the switch.
You can also check for continuity through the switch, should not be any.
My money is on Dan, bad switch.