Upgrading Trailer Wiring on a 2002 Toyota Sequoia from a Factory 4 Wire to a 7 Wire RV Plug
Question:
I HAVE A 2002 TOYOTA SEQUOIA AND HAVE A FACTORY TYPE 4 PLUG HARNESS AT MY HITCH.I NEED TO CHANGE TO A SEVEN WIRE AND NEED TO ADD A CHARGING POST FOR A TRAILER BATTERY AND MAYBE LATER ON A BRAKE CONTROLLER.I SEE U HAVE IT FOR AN 2005 OR NEWER BUT NOT A 2002.THANKS FOR YOUR HELP.
asked by: Danny S
Expert Reply:
To upgrade your 2002 Toyota Sequoia to a 7-Way RV style connector you will need to add a 4-Way to 7-Way adapter, like the Adapter 4 Pole to 7 Pole and 4 Pole, item # 37185. There is a 4-Way connector on the back of the adapter that you plug your existing 4-Way connector into, then you will need to hard wire the remaining wires. There is not a factory style 7-Way connector available for your model.
The black is for 12 volt power and is connected to the vehicle battery through a 40 amp circuit breaker, item # PK54540. The blue wire is for trailer brake power and is connected to the blue wire from the brake controller in the cab. The final wire, purple or yellow, is for backup lights or auxilliary functions, it is connected to the reverse light circuit behind the tail lights or to the proper auxilliary circuit. The white wire should be grounded to the vehicle chassis.
If you will be installing a brake controller, you can purchase the Brake controller Installation Kit, item # ETBC7, which includes all of the parts needed to hard wire a brake controller, the 12 volt wire and the auxilliary wire, this kit also includes the 4-Way to 7-Way and 4-Way adapter you will need.
If you are just wiring the 12 volt circuit at this time you will need to use an appropriate length of 10 gauge wire, item # 10-1-1, along with the circuit breaker mentioned earlier, to wire the 12 volt power circuit to maintain the trailer battery when towing.
If you decide to install a brake controller, I would recommend the Prodigy P2, item # 90885, brake controller. I have included instructions for wiring the brake controller and for the brake controller itself for you to review, along with a 2 part video installation that should be helpful. These instructions will also be helpful if you are only wiring your 12 volt positive wire.

Products Referenced in This Question
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 >
Tekonsha Prodigy P2 Trailer Brake Controller - 1 to 4 Axles - Proportional
- Trailer Brake Controller
- Proportional Controller
- Electric
- Electric over Hydraulic
- Automatic Leveling
- Under-Dash Box
- Dash Mount
- Up to 4 Axles
- LED Display
- Up to 360 Degrees
- Tekonsha
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 >
Pollak Circuit Breaker - Cycling/Automatic Reset - 40 Amp - Straight Mount Bracket
- Accessories and Parts
- Wiring
- Circuit Breaker
- 40 Amp
- Pollak
more information >
Product Page this Question was Asked From
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 >
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