Ford Bronco Air Horn Compressor Relay Wiring Diagram - Pins 30/85/86/87, 20A Fuse

This document is a hand-drawn (computer-sketched) aftermarket horn/air compressor wiring diagram uploaded to a 1986 Ford Bronco gallery. It shows how to wire a new relay to control a compressor (likely for an air horn) using the vehicle's stock horn circuit as the trigger. The blue factory horn wire that ran to the stock relay is cut and re-routed to pin 85 of the new relay (shown in blue). Pin 86 (green wire) connects to the other relay coil terminal. Pin 30 (red wire) feeds the compressor, which is grounded on its other terminal (black wire to chassis ground symbol). Pin 87 (yellow wire) connects via a red power wire through a 20 amp fuse to the positive terminal of the 12V battery. The diagram identifies each relay pin by standard DIN numbering (85, 86, 30, 87) and by wire color, specifies the 20a fuse rating, and includes the watermark 'Adrianspeeder.' A reader can learn the complete circuit path for triggering an add-on compressor from the stock horn button using a standard 4-pin automotive relay, including which factory wire to intercept and what fuse size to use.