BMW car alarm problems

To make a long story short, I had to disconnect the battery while doing some engine work.  When I plugged the battery back in the alarm goes off.  I wasn't the one who installed the alarm, and unfortunitly I don't have the remote to turn it off.  So I went under the dash and pulled out the wires going into the alarm.  The alarm turned off and I could start the car but when I went to lock the doors with my key, they will lock and then automaticly unlock themselves.  I am not aware of any other way to lock the car.  The alarm I disconnected is an aftermarket "prime mx3".  I've never heard of it and neither has the internet.  Any suggestions will be much apprieciated, as I refuse to leave my car unlocked.  Thanks in advance for the advice.

almost forgort, car is a '93 318i.