1997 dodge dakota security system won't shut off. How can I reset it or disarm it?

Had same issue for 1997 dakota truck I am looking to buy today. Been sitting for months with dead battery. Replaced the main battery and suddenly alarm went off. No matter what I did would not stop until I disconnected the battery. Like you I search the internet everywhere and combined several solutions into one. Here's what worked for me after making sure the batteries in the remote were good. I did this in the following in this exact order (per an internet mechanic expert this exact order or it will not work, you are resetting the system. It worked for me): 1. Connect battery ground only (disconnect the positive lead) 2. unlock and open both doors. 3. Insert key into the ignition and turn to the "on" position not all the way to start. 4. Connect Positive battery terminal. At this point either your alarm will sound and then shut off or no alarm will sound and you will hear any electronics engage that were left on. (Hopefully the latter.) If the latter happens start the engine. After the engines starts then it's OK to to Turn Off the engine. Close all the doors. Try your remote to the "lock" and "unlock" the doors. If they operate correctly the problem may have been solved. If the alarm still goes off after all this, it is one of the sensor switches in the doors (behind the door panels) that might be faulty or the control module which in that case is a "dealer" issue. I hope this solves you problem. I did for me.

Is it a factory system?