I'm having starting issues with my '08 Nightster and I'm hoping you guys can help. It seems like the bike will only start when it wants to and I haven't found a pattern to when it doesn't start or any issues with the electrical system. It'll do it after it's been sitting for a few days or when it's just sat for a few hours.

Background: So far I have checked voltage with bike on, voltage with bike off, stator, regulator, and the negative battery cable for continuity - it all checks out ok. I cleaned all the connections to make sure there was no corrosion and tightened all the connections. I keep the battery on a trickle charger most of the time and I've had 2 separate shops load test the battery - it tested good at both. The battery is an aftermarket replacement I purchased online and is about a year and a half old. The only thing that I thought was unusual was that with the ignition off there is a small current draw (~.6 mA if I remember correctly) that goes away if I remove the Battery fuse, I'm not sure if that's normal or not but I would think there should be current draw with the ignition off. I'm wondering if that small draw is discharging the battery enough to keep it from starting.

Symptoms: The bike has always turned over slowly when I hit the starter button, like it's struggling to get over the compression cycle, some times it'll start and other times it won't. I always hear the fuel pump pressurizing the line. If it won't start the charger will only turn the engine over once or twice and then stop. I can provide voltage, current, or resistance values if needed, I'm just not next to the bike at the moment.

Questions: Have you guys experienced anything similar? How did you fix the issue? Is there something else I should check? What would you try next? Should I have the starter checked out?

I just want to get out and ride! Thanks for the help.

 

07's & 08's were famous for corrosion in the fusebox, have you removed and cleaned both the fuse tabs AND each socket that the fuses go into, plus the tabs and sockets for the two big black square relays?

 

I removed all the fuses and wiped them off with a rag when testing where the current drain was but that was it. How should I clean the sockets? I'm not sure what I could fit in there.

 

I stole one of those hard cardboard nail files from the wife and whittled the end into a point and cleaned them with that then blew it out with compressed air and used di-electric grease on them.
The two black relays are important to do as well as one is a system relay, they are the same and interchangeable.
I was having all kinds of weird intermittent electrical issues before I did this and it's bee fine since, that was about 6 years ago.

 

Thanks! I'll be sure to try that when I get home tonight.

Nice looking bike by the way!

 

One more thing, do you know if you have that current draw that I described coming from the battery fuse circuit? If you do, how many milliamps are you pulling?

 

I would guess that the draw you are seeing is going to the speedo for the clock.

 

And the security system if equipped.

 

@HOTLAP, I cleaned out the fuse and relay connectors, the fuses and relays themselves, and all the wiring to/from the starter but it did the same thing - a super slow crank that dies out and doesn't get the bike started. The battery showed 12.7V before I started cranking and it quickly dropped to about 4.5V when I started cranking, which makes me think I have a bad battery, would you agree? I'm not sure why the battery would have tested fine at two separate battery stores that tested it though.

 

Sounds like a bad battery, get it load tested and any auto place.

rk classic