Tiny Flashing Blue Light on the left side A Pillar (2007 Eclipse GT)

For a little background my car has been having electrical issues for a while now, the problem would be that I'd open my car and get ready to start it but then when I'd turn the key all the lights and everything would just shut down. Went to AutoZone and they tested my battery and alternator and both were fine. Fast forward to today our mechanic comes and we try starting the car with one of those small jumpers, it doesn't work, he pulls the battery out of his truck and then we try to charge my battery and the car starts, but every time I open the door the loud theft alarm goes off and I can't shut it off with the remote key. Then I noticed that there was a small flashing blue light on the A Pillar that wasn't in the manual, the only light to indicate the arming system is on is the red light in the center on top of the dash. This is different, I can't open the door of my car without it going batshit crazy and even when I start it the alarm keeps going off. Even with the car unlocked the blue light on the left side A Pillar keeps flashing. Please Help.