My car will stall and horn blows randomly what could this be?

Hello, does the vehicle start back up when the stalling occurs? Although hands on testing is required, and no one online could possibly know in detail what is going on with your car without getting hands on to inspect -- it sounds like you are losing battery power or electrical power along the way from the charging system. If this happens, the reference voltage of the vehicle will go low enough to set off the anti-theft system inadvertently, causing the horn to blow. Low system power will also cause a stall. Just a guess. Hands on testing is definitely needed. www.repairpal.com/repair-shops