An ice cream truck bumped off my left parking headlight lamp in a small accident. As a result, the headlight lamp is left hanging on its wire but still works. Next, I disconnected the lamp. Later, I reconnected the lamp but after doing that, I now have a problem. Strangely, I could not disable my car alarm anymore (not sure if the alarm is OEM or aftermarket). If I disconnect the headlamp again, the car alarm could be disabled normally. Would anyone know how to solve this strange problem?