Auxiliary Spotlight Relay Wiring Diagram - 100W Lights, 20A Relay, 12V Battery

This document is a simple hand-style wiring diagram for adding auxiliary 100-watt spotlights to a vehicle using a relay. The trigger signal comes either from the high-beam switch or any 12-volt positive source, passes through an On/Off switch, and energizes a 20-amp relay. The relay's power feed comes directly from the positive terminal of a 12-volt battery through a 25-amp rated wire (shown with a fuse/resistor-style inline protection symbol), while the battery negative and the relay are grounded. From the relay's output, 10-amp rated wires feed two 100W spotlights, each with its own ground connection. The diagram teaches the standard relay-based method of wiring high-wattage auxiliary lighting so the heavy current load bypasses the factory headlight switch: the switch and high-beam circuit only carry the small relay coil current, while battery power flows directly through the relay to the lamps. Wire gauge/capacity guidance is given via the amp ratings (25 Amp feed wire, 10 Amp lamp wires) and the relay's 20 Amp rating. The diagram is generic and not tied to a specific vehicle year, make, or model, so it can apply to virtually any 12-volt automotive electrical system, including the uploader's 1998 Jeep TJ.