Fog/Driving Light Wiring Diagram with Bosch Relay, 20A Fuse & SPST Switch

This document is a simple color-coded wiring diagram (credited to Craig Ueltzen, 1999) showing how to wire aftermarket fog or driving lights using a standard Bosch-style relay. Power flows from the vehicle battery's positive terminal through an inline 20-amp fuseholder to relay terminal 30. Relay terminal 87 feeds the two fog/driving lights, each of which is individually grounded. Relay terminal 86 is grounded, and terminal 85 receives switched power from a SPST on/off toggle switch, which is fed by ignition or battery power drawn from the vehicle fusebox. A dash indicator lamp is wired off the switched circuit and grounded separately, so it illuminates when the lights are on. The battery negative terminal is shown grounded. The diagram identifies all five relay terminals (30, 85, 86, 87, 87A), specifies the 20-amp fuse rating, and labels every ground point. It is a generic installation reference not tied to any specific vehicle make, model, or year, making it applicable to most 12-volt vehicles including the uploader's 1995 Ford Bronco. Readers can learn the correct relay pinout, fuse sizing, switch placement, and grounding scheme for adding auxiliary fog or driving lights.