1988 BMW 528e 6 cyl Two Wheel Drive Automatic 175600 miles

I had an new car alarm installed Saturday, by Sunday my car just shut off on me while I was driving, but would not restart. I disarmed the alarm and got a boost, but my car still will not start. It's trying, but will not crank over. I think it has something to do with the alarm, but they telling me that my crankshaft is not getting power. Is they right?