12v 5 PIN change-over relay. A relay is used primarily to cut down voltage drop as power is taken directly from the battery to the headlights and the switch inside the car only operates the relay. The change-over relay should be positioned near the lights, or close to the fuse box. The relay is activated from the Main/Dipped beam switch. The main switch should also work through a relay. 30A @ 12V Maximum. The contacts are numbered 87 - 87a - 85 - 30 - 86. 85 and 86 power the relay through a switch and a 12v supply. 30 is common and typically connected to a 12v power supply. 87 or 87a carry the supply from 30 depending on the state of the relay (on or off)
