How to Wire a 7-Way Trailer Connector to a 2005 Chevy Silverado

Updated 03/17/2020 | Published 04/25/2015

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7- and 4-Pole Trailer Connector Socket w/ Mounting Bracket - Vehicle End

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Deka Jacketed 2 Wire, 10 Gauge, Brake Wire - per Foot

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Pollak Circuit Breaker - Cycling/Automatic Reset - 40 Amp - Straight Mount Bracket

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Hook Probe Circuit Tester

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Question:

the hopkins trailer replacement has 3 small wires, the truck has 4 small wires 2 of them are green 1 light green 1 dark green,

asked by: Clem

Expert Reply:

It sounds like you have found the bundle under the rear of your 2005 Chevy Silverado that would be used for wiring up a 7-way. In the bundle of wires, look for the following colors:

Yellow = left turn and brake light
Dark Green = right turn and brake light
Brown = tail lights
White = ground
Light Blue = not used (camper shell light)
Light Green = reverse lights

The definitive way to determine the wire functions is to use a circuit tester, # PTW2993, and test each wire while someone sits in the Suburban and runs through each function. The brake output wire and 12 volt power wire will not be present and will need to be run manually. The 12 volt wire will attach to the positive battery terminal via a 40 amp circuit breaker, # PK54540. The brake wire will attach to the blue wire of a brake controller. You can use wire # 10-2-1 and you will need about 25 feet worth.

The functions for a vehicle side 7-Way, if looking at the back of the plug where the wires connect, is:

1 oclock position = tail lights
3 oclock position = left turn and brake
5 oclock position = ground
7 oclock position = brake output
9 oclock position = right turn and brake
11 oclock position = 12 volt power
center = reverse lights

There may also be some connections that need to be made under the hood with you have a functioning 12 volt wire at the back and/or brake output wire. I have attached an FAQ article for you to view.

expert reply by: Jameson C

Raj

3/16/2020

I have a 2007 Chevy Silverado 3500 2wd classic. I don’t have any wiring under the truck for my trailer plug. What do i need to do to wire up a trailer plug with brake controller?

Chris R.

3/17/2020

It would be pretty odd/rare for your Silverado 3500 not to be equipped with some kind of factory trailer wiring. Is there by chance a round plug with a cap behind the bumper instead of a bundle of wires? If so, you would just need to plug in the Hopkins # 30955 to get your 7-Way and use the # 3015-P to install your brake controller (as long as it's a Tekonsha/Reese/Draw-Tite). Please just let me know if you still don't find anything and we can go from there.

Helpful Links

Accessories-and-Parts/Tekonsha/3015-P.html

Custom-Fit-Vehicle-Wiring/Hopkins/30955.html