Changed out rear cargo latcted h and when I shut the door it will nit open and when i hook up battery the alarm starts beeping. Any help or ideas will be appreciated.

 

It always helps to add your vehicle in your signature, year and model.

Assuming its a discovery 1 or 2-

Maybe the mechanism you switched out doesn't work and the alarm is a coincidence. Try drenching the mechanism from behind the logo on the rear latch with PB blaster and try to open.

Alarm- Make sure all the doors are locked. Push down plunger under hood that shows the hood is open, connect battery. If alarm goes off, try locking key fob.If no fob, lock driver door manually, then unlock.