I have a 2002 Fatboy that I bought used. I never had a key fob for it. The other day it started chirping in my garage. I deduced it was coming from the bike. I was able to find the fuse for the security system that I never knew it had. Of course it won't start without the fuse. I added it back in and it was chirping while riding down the road. Did the 2002 Fatboy have a key fob system that I just never had or is this trying to tell me something like get a new battery?

 

I suspect your system is the same as the ones on my '03 Heritage & '01 Springer...

The early bikes had a TSM, or you could order the optional TSSM with a security system.

The early systems used a FOB to arm, and then disarm the system. It was NOT a passively activated system. If you never activated it, you would never need to turn it off. The good news is that it's pretty easy to add a new fob to the early TSSMs, much easier than the newer models.

The early security systems also had an optional security alarm siren. The siren comes with an internal battery, so the siren will sound even if the battery is disconnected, if the alarm is activated.....

I believe you are hearing the alarm siren module "chirp" to let you know your internal alarm siren battery is dying.....

You should be able to disconnect the alarm siren module, if the alarm is not activated, with no consequence to the ability to start the bike....

 

Thanks for information! I suspected as much. I'll probably try replacing the battery and go for there.