Plan to install a Leer Harness 300200 for my third brake light, I have a 12 volt power question

[John E Davies]

EDIT 05/21/25: I bought the harness here: … https://www.mastercrafttruckcaps.co...tor-style-Wire-Harness-Leer-300200-p696351783

I need to connect my new third brake light on my Go Fast Camper Topper, I plan to use the Leer harness to tee into the OEM trailer brake wires. The kit comes with a long fused white power wire that should go to the battery Positive terminal.

My truck has an OEM fused 12 volt round receptacle at the left rear of the bed, directly where I would route my new harness. Is there any reason I should NOT connect the positive and a new inline fuse to that plug's positive wire? I can't think of anything, but these newer vehicles confuse the heck out of me...., Here is my truck:

Thanks for any comments.

John Davies
Spokane WA USA

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[Klutch]

That is likely a solution. There are also two aux wires down by the hitch wiring too . Aux 3 and 4 are down there. Just a heads up, using that T-connector may trigger the trailer detection on truck.

 

[Klutch]

https://www.ranger6g.com/forum/thre...t-think-it-has-trailer-behind-it.10716/page-2

See posts 27 and 31

 

[kvranger]

I have this exact kit. It will not make your truck think a trailer attached. I ran power from the battery because I wanted a light in my canopy that could be used without the truck being turned on. If that doesn’t matter to you, any 12v feed will work.

 

[John E Davies]

I have this exact kit. It will not make your truck think a trailer attached. I ran power from the battery because I wanted a light in my canopy that could be used without the truck being turned on. If that doesn’t matter to you, any 12v feed will work.

So do you think there would be no fit issues with the Raptor’s relocated 7 pin connector (under the bumper)?

Thanks.

John Davies
Spokane WA USA

 

[RANGER/HOBB]

I need to connect my new third brake light on my Go Fast Camper Topper, I plan to use the Leer harness to tee into the OEM trailer brake wires. The kit comes with a long fused white power wire that should go to the battery Positive terminal.

My truck has an OEM fused 12 volt round receptacle at the left rear of the bed, directly where I would route my new harness. Is there any reason I should NOT connect the positive and a new inline fuse to that plug's positive wire? I can't think of anything, but these newer vehicles confuse the heck out of me...., Here is my truck:

Thanks for any comments.

John Davies
Spokane WA USA

Can you post the actual URL for the connector please? They don’t have a search and I don’t see it readily available in accessories or anywhere else for that fact.

 

[John E Davies]

The kit is available at Leer dealers and a couple of online vendors. Here is the instruction sheet for it.

John Davies
Spokane WA USA

 

[John E Davies]

FYI I first installed this relocation kit, so my pictures may look a little strange. … Ford Ranger Trailer Plug Tuck Kit

I installed the Leer T Harness harness and it seems to work fine, I broke the retaining pin for the OEM plug

https://www.ranger6g.com/forum/thre...ch-replacement-part-number.19526/#post-281813

But otherwise it is straight forward job. I do wish that the inline rectangular “box” containing the diodes was cylindrical and smaller, the three smaller gauge Topper wires exit 90 degrees to the other main wires, and it is a really awkward design in terms of securing it. I ran the three Topper wires (Brake, Dome (2.5 amp max) and Ground ) and also the 12 volt Battery wire together up and over the frame, then up to the RR power sockets.

I added a Blue Sea Systems 5065 Waterproof In-Line ATO/ATC Fuse Holder with a 5 amp fuse to the back of the panel using a long 5mm bolt. I plan to add a rubber padded wire clamp onto those extra bolt threads when I finish routing the new cable.

I used an LED light that I am going to mount inside my topper as a test light, to make sure that both the dome and brakes work right, and I also used a 7 way plug in trailer circuit tester to make sure all the trailer functions are good, including constant 12 volt Battery Charge, Trailer Brakes and Back Up lights. I think this is a VERY important step, do it before you secure all the wiring.

Once you verify that everything works, you can fully tie down all the new cables and remove the fuse to kill power to the new harness, until you get around to finishing the job. I will post a couple more pics when I have this fully finished up top.

John Davies
Spokane WA USA

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