Troubleshooting Trailer Wiring on 2012 Ford Expedition
Question:
Bypass factory towing package and power trailer brake and turn lights off of 2012 Ford Expedition brake and turn lights?
asked by: Allen F
Helpful Expert Reply:
Your 2012 Ford Expedition should have a factory 7-way harness. There is a round connector called a US CAR connector that will allow you to have the wiring functions you need. If you need a 4-way, use # C55515 or if you want to add a 4-way in addition to your 7-way you can use # C55384. If you want a replacement 7-way use # C55774 which will give you both options.
If you are having issues with function, check your owners manual for fuse or relay issues if it is just a single function not working. There are many different fuses and relays to check on your vehicle.
If your fuses and relays are good I recommend checking your wiring at the round US Car Connector. The pin locations will match the 7-way I've attached for reference. You can use a circuit tester like # PTW2993 to test each function. If they work, then simply add a new harness like listed above. If not, then you can choose to tap into your factory wiring at the tail lights using a harness like the ZCI Circuit Protected Vehicle Wiring Harness with Installation Kit # 119250KIT which will protect your vehicle wiring. This will give you the 4-way trailer connector then you need the 7-way, you can use # ETBC7 which will help you with the additional wiring functions and is a complete kit.
If you have the factory 4 way and simply want to add the other functions, you will need the # 37185 and then you will tap into the factory 12V power and brake controller output wires found along the rear frame rail using # 10-1-1 sold by the foot.
Products Referenced in This Question
ZCI Circuit Protected Vehicle Wiring Harness w/ 4-Pole Flat Trailer Connector and Installation Kit
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- Converter
- Universal Fit
- 4 Flat
- Tekonsha
more information >
Curt T-Connector Vehicle Wiring Harness for Factory Tow Package - 4-Pole Flat Trailer Connector
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- No Converter
- Custom Fit
- 4 Flat
- CURT
more information >
Curt T-Connector Vehicle Wiring Harness for Factory Tow Package - 4-Pole Flat Trailer Connector
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- No Converter
- Custom Fit
- 4 Flat
- CURT
more information >
Curt T-Connector Vehicle Wiring Harness for Factory Tow Package - 7-Way and 4-Pole Flat Connectors
- Custom Fit Vehicle Wiring
- Trailer Hitch Wiring
- No Converter
- Custom Fit
- 4 Flat
- 7 Round - Blade
- CURT
more information >
Universal Installation Kit for Trailer Brake Controller - 7-Way RV and 4-Way Flat - 10 Gauge Wires
- Accessories and Parts
- Trailer Brake Controller
- Installation Kits
- etrailer
more information >
Product Page this Question was Asked From
Adapter 4-Pole to 7-Pole and 4-Pole
- Trailer Wiring
- Wiring Adapters
- Multi-Function Adapter
- 4 Flat
- Plug and Lead
- 4 Flat
- 7 Round - Blade
- Hopkins
more information >
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