Which relay terminal connects to the stock backup light wiring?

Terminal 86 (green wire) is the trigger, tapped from the stock backup light wiring; a manual override switch is also shown in this trigger line.

How are the new backup lights powered?

Terminal 87 (yellow) is fed by a new circuit from the 12V battery, and terminal 30 (red) feeds the new backup lights, which are grounded individually.

What is the manual override switch for?

It is placed in the trigger circuit so the relay (and the new backup lights) can be turned on manually, independent of the stock backup light circuit.

Does the diagram alter the stock backup lights?

No — the stock backup lights remain wired on the original circuit; the new circuit only taps the stock wiring as a relay trigger.

Home/ Registry/ Ford/ Bronco/ 1987-1991/ “The OJ Special”/ Photo supermotors.net/registry/media/485355

Auxiliary Backup Lights Relay Wiring Diagram with Manual Override - Ford Bronco

Backup light relay wiring diagram with manual override switch and color-coded wires

‹ ›

Wiring diagram adding backup lights via a relay and manual override switch with color-coded terminals.

AI caption February 2007 · Photo 136 of 297

This document is a hand-drawn (CAD-style) wiring diagram, watermarked "Adrianspeeder," showing how to add auxiliary (new) backup lights to a vehicle using a standard 4-pin automotive relay, uploaded to a 1988 Ford Bronco gallery. The diagram shows the stock backup light wiring (blue trace) feeding the stock backup lights at the bottom. A green trigger wire taps the stock backup circuit and runs to relay terminal 86 (green wire), while relay terminal 85 (blue wire) goes to ground. A manual override switch is drawn in line so the driver can energize the relay independently of the reverse circuit. Relay terminal 87 (yellow wire) receives power from a new circuit connected directly to the 12V battery (red trace), and relay terminal 30 (red wire) feeds the pair of new backup lights, each grounded on its own side. From this diagram a reader learns the relay pinout color coding (85 blue/ground, 86 green/trigger, 87 yellow/12V feed, 30 red/load), how to trigger auxiliary reverse lights from the factory backup circuit, and how to wire a manual override switch. The diagram is undated and does not state a specific vehicle application, so it is generic and usable on many vehicles.

Is this accurate? Sign in to help verify it.

Frequently asked questions

Which relay terminal connects to the stock backup light wiring?: Terminal 86 (green wire) is the trigger, tapped from the stock backup light wiring; a manual override switch is also shown in this trigger line.
Where does relay terminal 85 go?: Terminal 85 (blue wire) goes to ground.
How are the new backup lights powered?: Terminal 87 (yellow) is fed by a new circuit from the 12V battery, and terminal 30 (red) feeds the new backup lights, which are grounded individually.
What is the manual override switch for?: It is placed in the trigger circuit so the relay (and the new backup lights) can be turned on manually, independent of the stock backup light circuit.
Does the diagram alter the stock backup lights?: No — the stock backup lights remain wired on the original circuit; the new circuit only taps the stock wiring as a relay trigger.