Horn instead of Siren

Some alarms come with horn outputs that when you arm or disarm they sound like the factory systems (1 honk arms, 2 honks disarms or viceversa) I was wondering if it's possible to add that feature to a system that doesn't have that outuput and how should I do it. Thanks

just use the siren output on the unit to trigger a relay if you need explination on how to install if your doing it yourself let me know. if the unit does not have a parking light output you can use that to trigger a relay  to throw negative to the horn wire usually found at the steering column

thanks hit me up good luck