Red indicator light. Marked sign on the rocker for precise indications. This is Non-OEM Product. Accessory Only! Installation tips: . When installing, the groove of the green connectors clip is in line with the salient point of the black socket. . Press down the tail of the green connector a little for a convenient installation. Note: the color of the wires may be changed randomly, so use the clip as the location mark or use the black wire as the 4th wire. Wiring instructions: red: connect to + of ACC; yellow: connect to + of electric relay; red: connect to + of ACC; black: connect to iron on the car.