lo-jack question

[no-nos]

I had lo-jack installed about a month ago and for some reason the the car just turns off on me, and when you go to try to start it up again, it turns like if it's trying to start, but does'nt, the factory alarm also makes a faint skweeking noise like if the battery is dead and it does'nt have enough juice. I checked the alternator and the battery both are good

I guess i'll take it to my mechanic, and let him run some test on it, but if you guys could think of something, please do say, thanks in advace.