How to Hardwire a 12 Volt Accessory Outlet in a Truck Bed

Updated 09/05/2024 | Published 09/17/2017

Products Featured in This Question

12 Volt Outlet Kit, 20 amps

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12-10 Gauge Butt Connector

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$0.81

12 Gauge Wire - Black Primary - Per Foot

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$1.68

Ring Terminal - 12-10 Gauge Wire - 3/8" Ring ID

(76)

$1.84

LCD Digital Circuit Tester

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Spectro 12-Gauge ATC-ATO Fuse Holder - Qty 1

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Question:

Thanks for your help! I have a 2014 Chevy Crew Cab 1500 Silverado with a 6.5 foot bed and ARE topper. I would like to run a 12 volt accessory outlet to the bed of my truck. Can I pull this power off of my flat 4 or 7 way trailer connector? Im not sure of the proper wiring and if the accessory would be hot all of the time or just powered with the car running. Thanks again!

asked by: Tim J

Helpful Expert Reply:

Only a 7-way trailer connector will have a 12-volt power wire ran to the connector. A 4-way trailer connector will not have a constant 12-volt power wire. As long as the 12-volt power wire running to the 7-way trailer connector is rated for the amperage required for your 12-volt accessory outlet then yes, you can use this wire for powering the circuit.

Depending on how the vehicle is set up, your trailer connector may or may not still have power while the vehicle is off. To test this, you will want to use a circuit tester like part # PTW2992. Once you have located the constant 12-volt power wire (usually black) you will want to turn off the vehicle and see if the wire still receives power. If the wire still receives power while the vehicle is off, then the power is constant. If the wire does not receive power while the vehicle is off, then it only powers on upon startup.

In order to ensure you are receiving power constantly even while the vehicle is off and you have the proper amperage rating for the circuit you intend to run, I recommend wiring the outlet direct to the battery. For this you will want a few items which I have listed for you below.

12 Volt Outlet: part # RM-9332

12 Gauge Power Wire: part # 12-1-1 (Per Foot)

Butt Connectors: part # 05732-2

12 Gauge Fuse Holder: part # SWC9539

Ring Terminal: part # DW05705-1

Once you obtain all of these parts you will want to mount the 12-volt power outlet in the rear of your truck bed. After you have mounted the accessory outlet, you can ground the ground wire to a clean bare metal surface. Once the ground is connected you will need to use the butt connector to extend the power wire from the end of the outlet all the way up to the vehicle's battery. You can then use the other butt connector to attach to the fuse holder and a ring terminal to attach the fuse holder to the positive battery terminal. The fuse will need to be about 6" from the battery to work properly.