Rattler Car Alarm

1992 Chevy full size conversion van. Rattler alarm/door lock system installed when purchased new in 1992. Previous owners replaced battery in alarm controller attached to key ring. Alarm would no longer work. No installation instructions available. Opening doors with the key was next to impossible after so many years of relying on the controller. Any suggestions? Also, van battery went dead and upon recharge when key was turned in the ignition the alarm went off and would not shut off so I disconnected the wire to the siren.Stuey Dee

14 year old alarm....   Might be time to pull it and get a new one.  Othwerwise, you would need to check the power and ground connections.  Remote might need reprogrammed to unit if unit lost the remote somehow during the battery change.