Electrical Gremlins

[fly4hire]

OK, take off one afternoon for a ride, hot weather. Everything works. 30 miles later stop for a drink, get back on the bike and it won't start. Cranks, chugs, but won't start. Fuel pump working, dash lights and headlight not. Try everything - swapping relays, etc. Nothing. An hour later it mysteriously starts and I head for home. I pull into a local HD dealer for a second to make a call home. Now bike does not start again Battery acts near dead - clicky, clicky starter.

 

The tech manager throws in on a charger for 15 minutes starts right up. Checks voltage at the battery between 1000-3000. 12.5 volts. Damn, bad regulator. Order same, install, still 12.5 volts. Now I suspect a bad alternator.

 

Looking at shop manual it appears the charging circuit runs through the voltage idiot light on the dash and I'm getting no light, horn, or tach. Low voltage - no the battery was recharged at home to top off???

 

I start playing around with relays and relay connectors. After swapping a few and checking the wires I get the idiot lights, horn, and tach working, and check the voltage and Voila - 14.7 volts at 3500rpm.

 

Please tell me the there is not an interdependency between the charging circuit, idiot lights and the light relay??!!

 

Now everything is working fine, out for a ride a day later and the low fuel light comes on. Stop for a while a friends house and its the same start issue all over except this time the idiot lights work. There is a little fuel in the tank I can see shaking the bike around.

 

Now I'm wondering if perhaps there is a fuel feed or pump issue, however I can hear the pump loud and clear - maybe it's only feeding from one side? Suspecting this I lay the biker almost on it's side and back and she starts up (this is ~20 minutes later) and I make it (into a station 5 miles down the road. She takes 4.3 gallons. Starts fine and purrs (growls) as normal.

 

So now at this point do I have an independent issue with fuel supply, vapor lock, or could this be related to the earlier electrical problem?

[Buzzard]

My V11 is a 2002, it has an external fuel pump. If your bike does too, vapor lock may be your problem. Your experience is exactly what I had going on. I relocated my fuel pump, replacing it with a smaller, probably superior, definitely easier to mount elsewhere, pump. The stock pump, on some external pump models, is mounted right above the LH cylinder. You park the bike when hot, and it roasts the pump, boiling it dry. Takes about 30-45 minutes to cool enough to get fuel to flow. I hope this helps.

[fly4hire]

My V11 is a 2002, it has an external fuel pump. If your bike does too, vapor lock may be your problem. Your experience is exactly what I had going on. I relocated my fuel pump, replacing it with a smaller, probably superior, definitely easier to mount elsewhere, pump. The stock pump, on some external pump models, is mounted right above the LH cylinder. You park the bike when hot, and it roasts the pump, boiling it dry. Takes about 30-45 minutes to cool enough to get fuel to flow. I hope this helps.

 

 

Forgot to mention 2000 V11. The more I read I think you may be correct on the vapor lock. On my bike the pump is directly over the spine, however it was also blazingly hot days (90 +) and I tend to ride in the RPM sweet spot of 4-7K. The electrical relay stuff might have been secondary to the vapor lock, although I'm still curious about the charging circuit and light relay relationship....

[docc]

Yes, the light relay (second from front) gives a reference voltage to the regulator.

 

Look at the FAQ for a method on tightening the relay bases: Relay Base Repair