Dave, thanks for stopping by.
Did you install the smart siren II or the plain smart siren? Does it have an antenna on it and did you have the system already in and just add the siren or did you install the entire system?
This is the installation of the siren
Smart Siren II installation - Harley Davidson Community
The differences in the sirens.
Chirp/No Chirp Smart Siren Differences - Harley Davidson Community
Check out the self help forums with the link at the bottom of this post.
You can try this procedure too.
Alarm Chirp Mode (smart FOB) - Harley Davidson Community