Fuse Box Instructions for Installing a Brake Controller on a 2003 Chevy Silverado

Published 10/20/2017

Products Featured in This Question

12 Gauge 2 Conductor Jacketed (Brake) Wire Per Foot

(515)

$2.37

Tekonsha Plug-In Wiring Adapter for Electric Brake Controllers - GM

(1197)

$21.40

Deka Ring Terminal - Heat Shrink - 12-10 Gauge - 1/4" Ring ID - Yellow - Qty 1

(43)

$1.99

Deka Heat Shrink Butt Connector - 12-10 Gauge - Nylon Insulation - Yellow - Qty 5

(1124)

$7.44

LCD Digital Circuit Tester

(28)

$28.06

Question:

Thanks for the response. This would help me if I had all the Wire in that Video. Right now i only have one blue wire in the fuse box under the hood. With the Blue wire there is the Red Wire that follows that Blue wire from the Trailer Plug. If i dont have the Red Wire and Black Wire from Under the Dash do i need to pull additional wire from this Fuse Box.

asked by: Andrew A

Expert Reply:

Whether your 2003 Chevrolet Silverado came with a factory 7-Way or not, the wiring for both the brake controller and the 12V power pin on a 7-Way is already run. If you check out the video I attached of the Prodigy P2 # 90885 being installed on a similar 2003 Silverado you can see what needs to be done with the wiring under the fuse box at the 3:20 mark. You will just need to connect the Blue wires together and you will be good to go since you already took care of the Red wires.

The P2 uses a plug-in connector # 3015-P to install on your Chevy as you can see at the start of the same installation video. You will not need to run any wiring to your cab.

If you have 12V power to your 7-Way, then I imagine the wiring for your brake controller is already run to the 7-Way. To ensure that your brake controller is working correctly after it is installed you can perform this simple test. Using a Circuit Tester # PTW2992 on the 5 o'clock brake controller pin (see attached photo), set your brake controller to the highest power setting and apply the manual override lever. This will send 12V of power to that pin on your 7-Way which will in turn activate the brakes on your trailer.

expert reply by: Jon G

click to enlarge

Andrew A.

10/20/2017

Jon G.

10/20/2017

If you are unable to locate the Blue and Red wire that run to the brake controller then you can do some simple splicing to install your brake controller. What you can do is use an adapter specific for your brake controller, like part # 3015-P for the P2, and then splice into the wiring on the adapter. If you were to use the adapter I just mentioned then what you would do is splice Jacketed 2 Wire # 12-2-1 to the Blue wire and Black wire on the adapter and then route it through your firewall to the fuse box. You will then want to connect the wire from the Blue wire on the adapter to the Blue wire under the fuse box and then the Black wire from the adapter to the other stud under the fuse box for power. You can use Butt Connectors # DW05745-5 and a Ring Terminal # DW05740-1 to complete the installation.