Wiring for new Cap

[Shanewdude]

I’ve had my truck for two years now, and the tri-fold tonneau cover that I bought new with the truck is falling apart. Also, I’m looking to keep rain and snow off my tools, and make accessing tools easier. So I’ve bought a cap (topper?), and will pick it up this weekend.

Thanks to this forum, I think I’m well prepared for wiring it. The cap has canopy lights, camping lights, and USB charging that I will power with a harness from Wolfhaus.

That leaves the third brake, reverse and marker lights that I need to tie in to the driver side tail light.

I’m using tinned strand marine grade 14 AWG copper wire. I need 5 connections to the tail light harness, which I will make with T-taps. I’ve added heat shrink adhesive tubing to the paddle connectors, and will be using dielectric grease at the connectors. The other ends will get heat-shrink connectors. The whole bundle of wires are wrapped in a protective sheath.

At this point, I’m not sure how much room I have to make all 5 connections at the tail light. I’m also not sure if I will have enough room for the whole bundle to route it up through the bed.

I have found pin diagrams here in other threads, hopefully they are the same on my truck. It’s a 2022 Tremor Lariat, Canadian market, and if anyone has the pin diagram specific to my truck that might help reassure me. I’ll post the one I got from another post here again.

More pics to come when I start making connections.

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[Shanewdude]

Mods, perhaps this is in the wrong forum… feel free to move it or let me know and I’ll delete it and repost.

 

[JohnnyO]

I'd say use the 4-pin trailer plug if possible, then you only have to tap into the backup light wire.
That's what I did for my light bar.
I had a cap on the Sport Trac I used to own. It only had a third brake light, I got a cheap boat trailer wiring harness to run from the plug up into the cap. I found I needed a third brake light module (Amazon, $17) or the brake light on the cap would blink with the turn signal. You connect both turn signal wires to the module and one wire comes out (plus a ground) to connect to the third brake light.

 

[Shanewdude]

I'd say use the 4-pin trailer plug if possible, then you only have to tap into the backup light wire.
That's what I did for my light bar.
I had a cap on the Sport Trac I used to own. It only had a third brake light, I got a cheap boat trailer wiring harness to run from the plug up into the cap. I found I needed a third brake light module (Amazon, $17) or the brake light on the cap would blink with the turn signal. You connect both turn signal wires to the module and one wire comes out (plus a ground) to connect to the third brake light.

Thanks for the advice, definitely have to consider this. What is the advantage!

 

[JohnnyO]

What is the advantage!

It's easier than splicing wires.
For my light bar I popped out the left license plate light, ran the wiring harness under the bumper attached with a few zip ties to the 4-pin plug, then put the license plate light back in.

 

[Shanewdude]

It's easier than splicing wires.
For my light bar I popped out the left license plate light, ran the wiring harness under the bumper attached with a few zip ties to the 4-pin plug, then put the license plate light back in.

Ah, cool. I assume that I would have to unplug the cap then I tow something.

 

[RAYJAY]

I'd say use the 4-pin trailer plug if possible, then you only have to tap into the backup light wire.
That's what I did for my light bar.
I had a cap on the Sport Trac I used to own. It only had a third brake light, I got a cheap boat trailer wiring harness to run from the plug up into the cap. I found I needed a third brake light module (Amazon, $17) or the brake light on the cap would blink with the turn signal. You connect both turn signal wires to the module and one wire comes out (plus a ground) to connect to the third brake light.

can't will trip out the trailer towing sensors

 

[JohnnyO]

Ah, cool. I assume that I would have to unplug the cap then I tow something.

Unless a splitter exists, yes. But then the brake on the cap might not matter anyway.

 

[JohnnyO]

can't will trip out the trailer towing sensors

Which disabled the auto stop/start, so I don't have a problem with it.

 

[Big Blue]

Which disabled the auto stop/start, so I don't have a problem with it.

What it will do is disable the rear parking sensors and disable cross-traffic alerts and messes with your BLIS sensors. Not disable ASS, what disables the ASS is pressing the tow/haul switch.

 

[JohnnyO]

What it will do is disable the rear parking sensors and disable cross-traffic alerts and messes with your BLIS sensors. Not disable ASS, what disables the ASS is pressing the tow/haul switch.

Okay but I have a poverty-spec STX that doesn't have all the extra electronic stuff.
I can tell you that my tailgate light bar plugged into the 4-pin trailer plug does indeed disable the ASS without pressing the tow/haul button.

 

[Shanewdude]

It’s looking like T-taps into the tailight wires are the way to go.
Still open to other suggestions. Convenience is second to quality.

 

[Shanewdude]

Okay but I have a poverty-spec STX that doesn't have all the extra electronic stuff.
I can tell you that my tailgate light bar plugged into the 4-pin trailer plug does indeed disable the ASS without pressing the tow/haul button.

I thought about your suggestion, thanks for offering it. I do tow quite often, which is why I’m not going to use the trailer wiring.

 

[pismo1]

It’s looking like T-taps into the tailight wires are the way to go.
Still open to other suggestions. Convenience is second to quality.

For just the brake light.That is all I did and ground.Easy and took no time to do and no issues.

 

[Shanewdude]

Got the cap wired up (except utility and dome lights; waiting in the Wolfhaus harness).
The pin diagram is not identical to my 2022 Canadian market Lariat Tremor! It made me kind of nervous. Pin 9 is NOT blank! However, if you start at pin 1 and move up, pin 1,2,3,4and five are the same. I tapped into the ground, brake, parking, and reverse wires. Everything is working as it should.

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