Problem going on with my car. How do I fix this?

I own a 2 door 2000 Chevrolet Cavalier with a 2.2. Sometime when I am driving and hit a bump in the road just right (doesn’t have to be a big bump) the theft system light on my dash will come on. When that happens my daytime headlights will stay on even when I turn the car off. What I have been doing lately to make sure that my battery won’t run down is take an adjustable wrench and loosen the positive cable and it pretty much like resets the whole system. Just wondering if anybody knows how to fix this problem so I don’t have to do that. Thanks.