No sound on my viper alarm system

Replaced a old weak or wimpy horn on my van that has a viper alarm system installed. After replacing horn and verify it worked, the alarm all worked except that there is no sound coming off the new horn from alarm. Lights flash, car lockes, remote start work. But alarm which only sounds on my fob, will make no sound in my van. I suspect and hope its a fuse, but it's so disorganized under that dash...I need help please. I got health issues and getting upset is not good for me.