1996 Mazda 626 how do I disable the security system

1996 Mazda 626 ES mileage: 127,000. I recently purchased this car for my daughter and I do not have the owner's manual. There are two problems I have been unable to solve: 1. The car has an anti-theft feature. Locking the car door from the outside with the key causes a light on the dash to illuminate for about five seconds. The graphics on the light say "Security". After five seconds, the bell dings (sounds like the same bell that dings repeatedly with you leave the lights on and open the door). The light goes out but flashes on for a fraction of a second about every three seconds, apparently indicating that the alarm is activated. When you unlock the driver door with a key the alarm immediately goes off causing the horn to beep repeatedly and the lights to flash. Turning the key in the trunk lock deactivates the alarm. The local Mazda dealer said there was no factory security on the 1996 models. I believe it is factory since there's a light in the dash and the wire going to the trunk lock cylinder is clearly factory (part of the wiring harness, not spliced in). How do I disable the security system? Perhaps the car originally had a remote for the key ring, but I don't have one now. 2. The light for the air bag flickers on and off randomly as I drive. The Haynes book says that if there's a problem, the light comes on and stays on. I suspect there's a short or bad ground. How can I troubleshoot this problem?