Blowing 15 Amp ignition fuse

2009 Buell Xb12Ss 22,500 miles. EBR ECM + Drummer SS.

Today, while I was riding, the bike blew the 15 AMP ignition fuse. Let the bike totally cool off and replaced the fuse. 30-45 minutes later, while riding, blew the 15 amp fuse again. Swapped it, got 40 feet, blew again. Let the bike cool, put in a temporary 20 amp fuse to get me 2 miles to my house, removed it when I got home.

The bike ran coarse the whole way home.

So far, I have done a visual check of the wires under the fuse box, and wiring under the seat that is not wrapped in tape. I was thinking a frayed wire somewhere... Tomorrow, I want to test with the multimeter. Can anyone recommend a sequence I should test with, or perhaps have an idea of what may be going on?

The ignition fuse powers a lot of things on your bike. Look at the wiring diagram and trace where the power goes. Test each component in series and you will find the issue. It's not sexy, it's not fun, but if you jump around and guess it will cost you more money, and more time, than doing it right.

Bad unit with low resistance or gray wire shortened on the ground in the ignition fuse circuit. Check wiring diagram. It could be ignition relay, auxiliary relay, front or rear injectors, ignition coil, ECM, datalink socket, right hand control module. It could be injectors wire rubs the frame and shorten the ground. Follow gray wires from all that units list if it has stripped spot rubbing the frame or another wire.

Can anyone recommend a sequence I should test with, or perhaps have an idea of what may be going on?

classic XB symptom. i've covered it in perpetuity on here with causes, simple trouble-shooting and easy fixes.

lunaticfringe said:

Can anyone recommend a sequence I should test with, or perhaps have an idea of what may be going on?

classic XB symptom. i've covered it in perpetuity on here with causes, simple trouble-shooting and easy fixes.

Click to expand...

Can you please link me lunatic, I search for threads but can never find one that matches what I need.

Here is one from Lunatic,

" you have several possible issues causing this and all need to be checked. follow the list below that i am providing for you and report back with results. NOTE; on your ignition relay pins #30 and #87 transfer the current load. if only #87 looks charred or burned the problem lies with the female spades of the fuse box. if both 30 and 87 look charred or burned the problem is in the circuitry itself.
1-remove relay...CAREFULLY AND CLOSELY check the female spades of the fusebox that it plugs into. if corroded or worn that is typically the result of over-heating.
2-with new relay in place turn ignition key on...red run switch ON....and observe the gauge cluster. now wiggle the ignition key. anything weird going on in the cluster or fuel pump repeatedly priming? faulty ignition switch. replace same.
3-remove your stock flyscreen and carefully check all wiring bundles for chafing, shorts, bare spots, positive horn feed wire rubbing on horn bracket, chafing or frayed wires on the main harness feeding into the flyscreen area.
4-find ignition fuse in your fusebox. remove...check spades....check female sockets....clean and replace.
5-another known cause is over-charging problem. start bike...get heat in motor...pin a multi-meter onto the battery terminals...set meter to DC VOLTS...rev to 2500rpm and hold there....now check meter. you want 13.2-14.4 DC volts. anything outside that window you've got a charging system problem."

Here is the rest of it,

" was reasonably certain when you initiated this post that you would find, as i said, that the source of the problem was the connections/circuitry in the fusebox. with that in mind and apparently isolated and somewhat resolved...get yourself a spray bomb of kano kroil. it is truly amazing stuff. not cheap but money well spent. those female terminal ends a bitch to clean but if corroded/dirty....simply blow out what you can with compressed air nozzle....then fog with kano kroil...let sit overnite...blow out again with air....reinstall your relays....and give it a go. should resolve it for good."

The fuse began shorting once the cycle switch was flipped to run. So I took it over to my friends garage to start diagnosing... and we just started quickly freeing up the fuse relay box and all the wiring that connects to it and the ECM under the seat. We were able to decompress the wiring under there and it resulted in the 15 Amp ignition fuse not shorting. So we are pretty certain that the short is in that immediate area. Retarded ass location of the ECM wiring and fuse box wiring in the 12Ss. The seat compresses the cables and the ECM, its infuriatingly autistic.

Anyway, hopefully we will be able to find the culprit.....

Yes, Buell wiring management is horrible.

On the Lightning, the wiring and location of the ECM should be like it is on the Uly.

Found the culprit. Gray wire was frayed through at the bifurcation of the ECM cables. Also, an adjacent black wire was frayed through at the same point.

Yup, gray wire from that unit.

Good job finding it