alarm at battery connection

Hi - Dave here, contributing to RepairPal and providing expert advice since 2010. If you have sufficent battery power and the alarm is sounding - it sounds like turning the key in the ignition could shut it off, although sometimes it takes a bit more than that. It sounds like you have a factory antitheft system - which deactivates with a remote or fob, plus also by turning the key in the driver's and passenger's door cylinders (if equipped) and the ignition cylinder. If this does not cut off the alarm, it may have an aftermarket one installed also - which you can get removed with the help of a shop near you -- https://repairpal.com/auto-repair-near-me Click the link to find some shops near you who can help out!