Anyone have any input on why the red security light stays illuminated on a 2018 Softail Street bob ?
We have tried everything and cannot get it to turn off.

 

A red security light is a sign of an electrical issue...

Check for burnt bulbs, or maybe a bad brake light switch. I think I read one time that on the BCM bikes it will light up if the key FOB battery is weak, but I could be remembering that wrong.

Did you check for codes?

Good luck with your diagnostics...

 

Maybe the fob when was the last time you replaced the battery

 

There might be an explanation in the owner's manual.

 

This just happened to me yesterday on the way to meet guys for our weekly ride.

I just put new handlebars on and check everything when I was done. After 5 minutes of troubleshooting, I found that the switch for the front brake came unseated from it's mount and the brake light wasn't disengaging. It's funny because I put the tools to take off the brake lever assembly and the switch housing in my saddlebag - just in case. I had 10 minutes before Kick Stands Up and was able to remove everything and reseat the brake switch. Bingo, security light out.

Check your brake switches are working or you might also have a burned out bulb.

 

Access the dtc trouble code screen on your speedometer and that should give you a starting point.
A forum search should describe how to do this.

 

Also, any recent electrical work, or bar swap? Many have fk'd up wiring, grounds & switches, if you don't know what you're doing.

 

I had that, it was the brake light switch. I replaced it, and it solved another problem also, the cruise control was kicking out.