I have recently purchased this bike and I´m in the process of restoring her back to it´s original state but I´m having trouble getting info on the alarm system. When the system is activated and the ignition switch is tampered with, like inserting a key into it, the horn sounds and the light flashs. Now, under the seat there´s a small black box with a plunger sticking up with a 5 pin terminal block located on top of the fuse and relay box which seems to do nothing. What is it´s purpose???