03 denali compustar pro battery problem

Hey Guys, I had a customer with a 03 Denali (Yukon) come in and we installed the Compustar Pro in there. Everything is working properly, but he called me a couple days back and let me know when he arms the vehicle the night before by morning the battery is dying. I told him to not arm the truck overnight and his battery was fine this morning. I know I have the relays wired properly I tested them and they are all fine, and am now wondering if this could be a BCM Issue,does it shut down on these or not, or If I have tapped into a wire that is keeping the BCM on? or can it be a bypass issue? I tested that aswell and only the 12v is showing power as it should. He lives out of town and want to save him a trip if I can. any help is greatly appreciated. thanks in advance.Never argue with an Idiot, they will bring you down to their level and beat with you with experience.