For the fusible link of the lights etc. circuit on ambulances with high specifications, the capacity is insufficient and the shape of the terminals is improper, and therefore, continuous use of the electric system with high load can cause the terminals to heat. The heat can cause the resin of the terminals to melt, and the melted resin may go between the terminals breaking electrical continuity, in which case the head lights, width indicators, break lights, hazard lights, horn, and/or defroster may fail to illuminate or function.