When looking at the (where you insert the wires), the pins are arranged in two concentric circles.
If you tow a caravan or boat trailer with or electromagnetic brakes , pins 6, 9, 10, 11 are vital. ford ranger 12 pin trailer plug wiring diagram
| Pin # | Function | Color Code | | --- | --- | --- | | 1 | Left Turn Signal | Yellow | | 2 | Left Brake Light | Red | | 3 | Left Tail Light | Brown | | 4 | Right Turn Signal | Green | | 5 | Right Brake Light | Red | | 6 | Right Tail Light | Brown | | 7 | Running Lights ( Aux) | Brown/White | | 8 | Fog Light (Optional) | Grey | | 9 | Battery Feed (12V) | Orange | | 10 | Ground | White | | 11 | Electric Brake | Blue | | 12 | Reverse Light (Optional) | Purple | When looking at the (where you insert the
| Function | Fuse | Relay | Location | |----------|------|-------|----------| | Trailer left/right | F24 (15A) | – | BJB* | | Trailer tail | F23 (15A) | – | BJB | | Trailer reverse | F18 (15A) | R6 | BJB | | Aux power (pin 7) | F30 (30A) | R5 | BJB | | Ignition aux (pin 8) | F29 (20A) | R7 | BJB | | Brake controller (pin 9) | F8 (10A) | – | Cabin fuse box | The wire needs to run from the controller output to the plug
| Step | Action | Expected Result | |------|--------|------------------| | 1 | Ground test lamp to chassis, probe pin 3 | Lamp lights when any circuit active | | 2 | Turn parking lights ON → probe pin 5 | +12V | | 3 | Left turn signal ON → probe pin 1 | Pulsing +12V | | 4 | Right turn signal ON → probe pin 4 | Pulsing +12V | | 5 | Reverse gear (engine on) → probe pin 2 & 10 | +12V (both) | | 6 | Brake pedal pressed → probe pin 1 & 4 | +12V (both) | | 7 | Aux power check (engine off) → pin 7 | +12V constant | | 8 | Ignition ON (engine off) → pin 8 | +12V switched |
Don't forget that the blue wire on Pin 4 does nothing unless you have an Electric Brake Controller installed inside the cabin of the Ranger. The wire needs to run from the controller output to the plug.
Ensure your Ford Ranger is turned off. Locate the towbar wiring harness. On most Rangers, the factory harness will usually provide a 7-pin flat socket or a 13-pin socket (depending on the market). You may need an adapter or to hardwire the 12-pin socket directly into the vehicle loom.