Wiring 3rd Brake Light on Truck Bed Cap for 2015 Chevy Silverado 1500

Question

Question:

I bought a cap for my truck and I cant find any information on how to wire the brake light on the cap or what parts I need. I would also like to purchase and install an interior light bar inside the cap. The cap has 2 wires - 1 blue, 1 black. Can you help?

asked by: Mike S

0

Expert Reply:

If you follow wiring harness feeding the 7-way trailer connector from the bumper up toward the spare tire and peel back the wire loom, you should be able to find an additional blue wire in the harness. The blue wire carries the 3rd brake lamp signal for your bed topper.

For the interior dome light, you can get 12 volt power from the black wire feeding the trailer connector. You'd want to install a switch on the circuit like part # PK34513.

One of the wires would be power, the other ground. The black wire is most likely the ground, but you could test it by applying 12 volts to the blue wire and grounding the black one. You could also call the topper manufacturer, and they'd be able to tell you.

expert reply by: Mike L

0

Geovanbi

2/20/2020

So for brake light where do you get the ground from. I know blue positive but what about negative

Jacob H.

2/20/2020

The white wire is going to be your ground wire. It is recommended that you ground it to the battery.

Mike H.

5/25/2020

When looking for this blue wire do you have a picture of where it would be? I see the trailer brake blue wire, i'm not seeing another blue wire.

Chris R.

5/28/2020

Unfortunately I don't have a picture available of that blue wire. It'll be a bit further up the truck than the blue brake output wire you found. If you can't find anything - I would just start testing different wires in this area for function (it's possible it's just a different color on your truck). See which one gets power with the brake lights on.

Answer 1

On your 2014 GMC Sierra 1500 there is a junction box with a black cover on it located on the driver's side floorboard, way in the back, to the left of the brake pedal. There should be an empty spot to plug in the wiring harness located in the…

view full answer...

Answer 2

Sometimes there is a blue wire in the loom of the 7-Way but if you are not seeing one that likely means that there is an orange wire under the dash on the driver's side of your 2015 Chevrolet Silverado 1500 that you need to use. This should be…

view full answer...

Answer 3

To power the third brake light of the camper shell on your 2015 Chevy Silverado you are going to need to tap into the CHMSL (center high mount signal lamp) circuit of the truck. If you check the diagrams of the fuse boxes of the truck you should be…

view full answer...

Answer 4

The easiest way to use your vehicle's 7-way trailer connector to power up the third brake light on your truck cap is to first locate the right and left turn signal wires behind your 7-way. Then simply tap into those and install the Pacer…

view full answer...

Answer 5

I'm pretty sure that's to wire up a third brake light on a camper shell. To know for sure, take a circuit tester, like our part #PTW2993, and test that wire while applying the truck's brakes. If I'm correct it's a dedicated brake…

view full answer...

Answer 6

Based on my research, it looks like both the previous generation and later model years of the GMC Sierra featured easy to reach wiring for the dedicated brake light circuit on the truck. For your 2014 model Sierra though, these wiring harnesses are…

view full answer...

Answer 7

The Curt T-connector #C55384 has a 4-Way flat connector on it. The functions that it carriers are running lights, left turn/brake lights, right turn/brake lights, and ground. If the dome light runs off of the running light circuit and the wiring on…

view full answer...

Answer 8

Since your trailer uses a combined wiring system where the stop and turn signals run on the same circuit, in order to add a third brake light to your trailer you would need to use a 2-Wire to 3-Wire Converter, like part #118158. This will convert the…

view full answer...

Answer 9

The difference between the Class II and Class III hitches has to do with their Gross Trailer Weight (GTW), their Tongue Weight (TW), and their Hitch Receiver Size. Class II trailer hitch receivers have a 1-1/4 inch receiver and can be rated up to…

view full answer...

Answer 10

A 4-Way trailer connector has the basic lighting functions only; running lights, left turn signal and brake lights, right turn signal and brake lights, and ground. A 7-Way has these functions and a 12 volt circuit, a circuit for electric trailer…

view full answer...

Answer 11

Hey Jonathon thank you so much for all of that additional information! To haul your bikes behind your class C Sprinter motorhome, while flat towing your Mini, I recommend the Hollywood Racks RV Rider Bike Rack item #HLY64FR and the Roadmaster Dual…

view full answer...

Answer 12

Hi Paul, you’re definitely on the right track here, and I can help you narrow this down with confidence. With your tandem 3,500 lb Dexter axles and 33 inch spacing, both the Dexter EZ Flex part #K71-652-00 and the Lippert Road Armor part #LC53CK are…

view full answer...

Wiring 3rd Brake Light on Truck Bed Cap for 2015 Chevy Silverado 1500

Products Featured in This Question

Featured Help Information

Miscellaneous Media

Continue Researching