HI -
Posting this for anybody who has this issue:
I had this problem for quite a while, No matter what I did I could not stop the battery from draining quickly. It eventually got so bad that the battery would drain in 3 days. I just kept the charger on it.
In troubleshooting I figured out that somewhere, a door sensor was not allowing the alarm to arm. Tis was not obvious, except that the little lights in the door lock pins would not illuminate. Long story short, I discovered that the issue was in the shocks for the rear deck, which I had replaced a year before, do not open the contact to ground for the alarm when the deck is closed. There is a plastic sleeve that should open the contact but it's either too short or something else is up. It thinks the rear deck is open. Therefore, the system doesn't arm and sucks battery power. I resolved this by pulling the wire off the connector. Voila!