Need Help with 06 Buell Xb12sx Ulysses: Fan Won’t Stop Running

[samuelseggs]

Hello everyone,

I'm having issues with my 2006 Buell Xb12sx Ulysses and could use some advice.

During a recent interstate trip, I had both headlamps on. Just before reaching my destination, I stopped to refuel and noticed that my bike wouldn’t start—the battery was low. Thankfully, I had my Baseus Super Energy 2-in-1 Jump Starter 1000A in my travel box (I usually use it to gauge my tires on long trips), so I jump-started the bike, and it started right up.

I arrived at my destination, and the fan was still running, but I didn’t think much of it since that’s not unusual. However, the next morning, the battery was completely dead again. I used the jump starter to get the bike running, but this time, I noticed that the fan started running immediately when I plugged in the jump starter. This got me concerned.

I rode for about 30 minutes, and even after turning off the bike, the fan kept running. I started the bike again, and it fired up without any issues, so I know the charging system is working. However, the fan continues to run unless I remove the fuse.

A few days later, I swapped out the ECM with my old one, reinserted the fan fuse, and the fan started running again.

At this point, I’m not sure what else to try. Has anyone experienced something similar, or does anyone have any suggestions on what might be going wrong?

My Buelltooth is bad, so I'm unable to read the ECM for any error code

Thanks in advance for any help!

 

[Cooter]

That is a common issue after hooking up a battery or a jumper backwards. I believe your early bike has a direct connection to the ECM signal (ground wire to the fan) and no fan relay.

1) Your ECM's are 'stuck on' internally because they have been fried by hooking up a battery backwards.
-or-
2) Something else is 'stuck on' and telling the ECM to turn on the fan.
-or-
3) the Black/Orange wire to the fan has been shorted to ground

Try unplugging the temp sensor and see if the fan shuts off. Yes, replace the sensor. NO, test the B/O wire for continuity, or replace with a good ECM. I doubt theres and code for this, but this would still be easier and more accurate if you fix your Bluetooth.
2006 cooling fan diagram:

from here:
https://buellmods.com

 

[samuelseggs]

Thank you, Cooter. Just as you suggested, I found that the fan was shorted to ground.

Due to the heat, the black wire melted and came into contact with the bike's body, causing the fan to keep running.

The issue has been resolved. I took the bike for a ride, and the fan is functioning normally again.

A bit of background:

I've been dealing with issues with my bike for quite some time, which led me to replace the ECM. Unfortunately, that didn't solve the problem. On long rides, the red light would start blinking, and the bike's speed would drop until I turned it off and let it cool down. Despite trying various solutions, nothing seemed to work.

However, during my recent trip, when the fan kept running, I noticed the bike didn't exhibit the usual issues—no blinking red lights, and I was able to maintain top speed.

Now that the problem is fixed, I have another trip planned for Monday. I'll provide an update afterward to see if the blinking lights return.

During the troubleshooting period, I used the Bluetooth device to scan for errors, but no codes appeared.

 

[Cooter]

Congrats! Happy it worked out for you:applause: