Ford Crown Victoria Fog Light Relay Wiring Diagram - Lowbeam Trigger & Override

This is a hand-drawn (computer-sketched) DIY wiring diagram for adding fog lights using a single automotive relay. The design taps the demand lighting circuit from the glovebox lamp (upstream of its switch/latch) and uses a switched lowbeam +12V feed to energize the relay coil (terminals 85/86), so the fog lamps come on automatically with the low beams and turn off with high beams (since lowbeam power is cut with highbeam). A four-position switch control box provides a manual fog override, wired through a diode to prevent current backflow from the override circuit into the lowbeam circuit. With the override pressed, fogs can operate without any other lights, or even with the car off for about 20 minutes until the LCM (Lighting Control Module) cuts off the demand circuit. The relay's terminal 87 feeds the two fog lamps, which are grounded on the far side; the relay and lamps have chassis grounds shown. A note indicates the relay setup should be repeated for each accessory. The diagram uses colored wires (green demand tap, yellow lowbeam feed, blue override, red power/output, black grounds) and shows two diodes: one at the lowbeam feed and one in the override line. Useful for anyone wiring relay-controlled fog lamps tied to lowbeam operation with manual override on an LCM-equipped Ford.