What are the standard trailer wiring colors?

Per this chart: Green = right turn, Yellow = left turn, White = ground, Brown = tail/marker, Blue = brake, Red (or Black) = battery, Purple = back up.

What wire gauge should I use for trailer brakes?

The chart suggests a minimum of 18 gauge for 4-way and 5-way connectors and 12 gauge for 6-way and 7-way connectors for the blue brake wire.

Where does the white trailer wire connect?

The white ground wire attaches to a vehicle ground point that is metal, uncoated, and rustproof on both the vehicle and trailer sides.

Which circuits are on a 4-way trailer connector versus a 7-way?

A 4-way carries right turn, left turn, ground, and tail/marker. A 5-way adds brake, a 6-way adds battery, and a 7-way adds back up.

Where should the red battery wire be attached on the vehicle?

To the fuse block or a FUSED battery lead; on the trailer side it goes to the breakaway kit, interior lights, and battery charger.

Home/ Registry/ Ford/ Bronco/ 1987-1991/ “Eddie Bauer”/ Photo supermotors.net/registry/media/859885

Trailer Wiring Color Code Chart - 4, 5, 6 & 7-Way Connector Wire Colors & Gauges

Trailer wiring color code chart with function, wire color and minimum gauge for 4/5/6/7-way connectors

‹ ›

Reference · 1987-1991 BroncoAll 175 wiring diagrams

Ford E4OD Transmission Connector Pinout Diagram - Pin & Wire Color Chart

1990 Ford Bronco Horn & Cigar Lighter Wiring Diagram 44-1 (With/Without Cruise)

1990 Ford Bronco 5.0L Grounds G103 Wiring Diagram - EEC & HEGO Ground Circuit

Trailer Wiring Color Code Chart - 4, 5, 6 & 7-Way Connector Wire Colors & Gauges

4-Pin Flat Trailer Wiring Diagram - Wire Color Codes & Light Functions

Ford E4OD Test Harness T89T-70100-A Terminal Locations & Wire Color Codes

Ford PMGR Starter Wiring Diagram - Relay, Solenoid & Cable Gauge Instructions

Ford Mini Starter (PMGR) Relay Wiring Diagram - 5-Pin Relay, 20A Fuse, Wire Gauges

Ford 3G Alternator Wiring Diagram - Mega Fuse, Charge Lamp & Wire Colors

KC Driving Lights & LED Light Bar Relay Wiring Diagram - Ford Bronco Aux Lights

175wiring diagrams1987-1991 Ford Bronco More reference

Ford Thermactor Air Bypass Valve Cutaway Diagram - Port Identification

Schematic

Ford Canister Purge Regulator Valve (CANP 9C915) Test Procedure - Figure 11

Service procedure

Ford 5.8L important engine information decal with 10° BTDC timing check and ASF-32C plug

Spec plate

Ford 5.0L V8 PCV Valve & Hose Routing Diagram - 9A474, 6B890, 6A664

Exploded parts

Ford 5.0L/5.8L Air Throttle Body Assembly Diagram - Canister Purge Ports & TPS

Manual page

1990 Bronco Major Standard Equipment sheet with interior features and functional specs by trim

Brochure

Borgeson Steering Intermediate Shaft Measurement Diagram - U-Joint Length B & C

Blueprint

Ford Thermactor Combination Valve Diagram - Air Bypass/Control Ports Labeled

Vacuum routing

1990 Ford Bronco Fuse Panel Diagram: Fuse Positions, Amps & Circuits (11-2)

Fuse chart

Ford V8 Intake Manifold Bolt Tightening Sequence Diagram - Stud Locations

Torque spec

Trailer wiring color-code chart mapping connector functions to wire colors and minimum gauges: right turn green, left turn yellow, ground white, brake blue, battery red, backup purple.

Part of 1987-1991 Ford Bronco Wiring Diagrams

AI caption April 2011 · Photo 637 of 1787

This document is a trailer wiring color code reference chart covering 4-way, 5-way, 6-way, and 7-way trailer connectors. For each circuit function it lists the standard wire color, the suggested minimum wire gauge (given separately for 4/5-way and 6/7-way connectors), and where to attach the wire on both the vehicle side and the trailer side. The functions covered are: Right Turn (green, 18/16 gauge), Left Turn (yellow, 18/16 gauge), Ground (white, 16/12 gauge, attached to a metal, uncoated, rustproof ground point), Tail/Marker (brown, 18/16 gauge), Brake (blue, 18/12 gauge, connecting the electric brake controller to the trailer's breakaway switch), Battery (red or black, 12 gauge, from a fuse block or fused battery lead to a breakaway kit, interior lights and battery charger), and Back Up (purple, 16 gauge, from the vehicle's backup circuit to backup lights or a hydraulic coupler). The nested connector column shows which circuits apply to each connector type: 4-way connectors carry only turn, ground, and tail circuits; 5-way adds brake; 6-way adds battery; 7-way adds backup. A footnote warns that wire colors may vary by manufacturer and recommends verifying connections with a circuit tester.

Is this accurate? Sign in to help verify it.

Frequently asked questions

What are the standard trailer wiring colors?: Per this chart: Green = right turn, Yellow = left turn, White = ground, Brown = tail/marker, Blue = brake, Red (or Black) = battery, Purple = back up.
What wire gauge should I use for trailer brakes?: The chart suggests a minimum of 18 gauge for 4-way and 5-way connectors and 12 gauge for 6-way and 7-way connectors for the blue brake wire.
Where does the white trailer wire connect?: The white ground wire attaches to a vehicle ground point that is metal, uncoated, and rustproof on both the vehicle and trailer sides.
Which circuits are on a 4-way trailer connector versus a 7-way?: A 4-way carries right turn, left turn, ground, and tail/marker. A 5-way adds brake, a 6-way adds battery, and a 7-way adds back up.
Where should the red battery wire be attached on the vehicle?: To the fuse block or a FUSED battery lead; on the trailer side it goes to the breakaway kit, interior lights, and battery charger.