1999 Hyundai Sonata, I cleaned the battery connections and pasts and when I tried to hook everything back up the anti-theft alarm went off and I can't get it to stop. What process do I go through to reset the system?

is it after market alarm?

try putting the in driver's or passanger's door lock, and lock and unlock it, this is with all doors closed. if you have a remote, try doing the same with it.

do it wile the alarms going off.

I did and the alarm silenced after about 30 sec. or so, then when I opened the door the alarm went off again.

ok, so we know the door switches are not the problem, lets see what next? i'm going to call my buddy pete, he's a dealer boy. as a rule the door switch is a reset for the security, but i left that dealer many years ago, so not 100% sure. i'll let you know, mws919

got it fixed, closed doors put key in ignition in run position, pressed unlock on remote and simuntaniously moved the toggle valet switch. Thanks for you'r help.