The plus or minus of wiring was difficult to understand. Normally there is a perception that a line with a white line in the wiring is negative, but in reality it was positive. However, it seems that a miswiring prevention circuit is built in and it lighted normally even after making a mistake. Since the insertion of the wiring coupler was a little sweet, I fixed it with adhesive and wound the shrinkable tube. Also, it seems not to bend in the horizontal direction.