2004 Buell xb12s not starting

[blazer guy]

Hello, i just bought an 04 buell xb12s with 7,200 miles yesterday and took it for a test ride and it worked fine. Brought it home and left on about a 25 mile ride and it started acting weird. It would start stumbling where it wouldn't rev and the cel would flash on dim then shut off or stay on for 10-15 sec then shut off. The stumbling was intermittent for about 10 miles. Then i was riding along at about 40 and the bike just died on me.

Bike will turn over but will not start. When i move the key to the on position the neutral light and oil light come on but the tach, speedo do not sweep and the odometer does not light up. Sometimes when i turn the key to the off position the speedo and tech will sweep after about 3-4 seconds. When i turn the kill switch to run the fuel pump does not prime. It will turn over but does not start. Also turn signals are working but the indicator light does not light up showing them on. The passing light only works when the high beam is on lighting up the low beam.

i have tried to pull codes but when i jump the two prongs in the plug and turn the ignition on the cel will not light up at all after 8 seconds. I have checked and replaced the relays and they all seem to be working, all of the fuses are good. All lights and turn signals are working. Battery is fully charged. all of the grounds under the seat are connected and not loose.

I am stumped as to what to check next. I have an ecm cable ordered and on the way but it will be a few days before it gets here. Any help or direction as to what to do next is greatly appreciated.

 

[Cooter]

With all those different electrical problems in different circuits it Sure sounds like a wiring problem to me.
Turn it key on and grab the harness by the steering neck and move it around. Do things change?

 

[Chicknstripn]

I would check the battery voltage while the bike is running.
Without the engine on you should be real close to 13volts. Same when engine is idling. At around 2k rpm you should see something close to 14volts. Hold at 2rpm, does the voltage drop? If so you have an issue with either the battery or your charging system.
So some research on charging system issues and you'll find posts similar to yours.
Keep the investigation going and let us know what else you discover.

 

[blazer guy]

Well after spending all day working on it I got it running again. I had cleaned all of the grounds thoroughly and reconnected them but I came to find out after testing the continuity of the grounds the throttle side ground on the subframe was not acting as a ground. I ran a jumper wire from the ground on the other side of the subframe and everything works correctly as it should now. This is a temporary fix until I start looking through the wiring harness for the real cause of the problem. Just glad to have it running again.

 

[Cooter]

Sounds like that is the real cause of the problem? A good ground strap is easy to duplicate, unless you just want to go the OE route.
Glad you found the problem and thanks for posting the solution.

 

[user_deleted]

Well after spending all day working on it I got it running again. I had cleaned all of the grounds thoroughly and reconnected them but I came to find out after testing the continuity of the grounds the throttle side ground on the subframe was not acting as a ground. I ran a jumper wire from the ground on the other side of the subframe and everything works correctly as it should now. This is a temporary fix until I start looking through the wiring harness for the real cause of the problem. Just glad to have it running again.

most fail to understand what a ground on a negative earth motor vehicle does. electron/current flows FROM the negative ground to and thru the source it is powering....thru source...then to the positive side of the battery......NOT the other direction which is common belief. the negative ground is clearly much more than, and is NOT a completion of the circuit. your bike has multiple grounds including several near the battery and its' negative cable ground source at frame....the dog-bone braided ground...and front of headlight bucket area at either the bottom triple clamp or steering neck. they all need to be clean, tight, checked and verified. also recommend you run a dedicated wire from the rear-most engine coil mounting cap-head bolt directly to the negative battery cable ground source. resolves alot of low-speed jitters and starting issues.