Properly "Splitting" Wires

[SwampSurvivor]

I'll be wiring up my car trailer soon. Like pretty much every other set of trailer wiring, there is only one run of tail light and turn signal to each side.

It's over 80'' wide, so I'll need to split off a few times for 3 small marker lights on each side (LED) , the middle ID light (LED) and the two tail lights (incandescent).

This is the harness I bought. https://www.etrailer.com/Wiring/Optronics/A35W42B.html

What would be the best way to "split" the wiring off to each light. I would like to do it right so I'm not having to play with wiring each year to get it inspected or being that guy on the road with trailer lights that don't work.

I would like to use this style of connector link to hook all of the lights to the main wiring circuit so they are easily replaceable should anything happen.

What would BITOG reccomend? All connectors will be lathered in dielectric grease. I imagine I would need some sort of 3 way splitter? Ideally something that can work with the connectors I'm using. I do not want to do the T Taps, my camper has those and they are awful.

 

[123Saab]

Splice by hand if you dont want to use T-Taps.

 

[supton]

I was kinda surprised with the crimp connectors I got from HF, they feel not so bad. I have a halfway decent crimper and so far I'm ok with the results. Cheap crimp connectors get cheap results, usually I aim for 3M connectors, but these HF ones felt like they might hold up.

if you want it to last, solder on clean copper. Recently I found a local vendor with heatshrink tubing with adhesive on the inside, for making watertight sealing. I have a few pieces of that around for such jobs.

 

[exranger06]

Buy these butt connectors:
https://www.amazon.com/gp/product/B07M5WG5KD/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1

Cut the wire where the splice will be, so you have 3 individual wires (1 wire splitting off into 2 wires). Strip about 1/4" insulation off all the wires. Take the two wires that are splitting off and twist them together. Insert the twisted end into one side of the butt connector. Insert the "supply" wire into the other end of the butt connector. Use a heat gun on the butt connector. The solder will flow out and fuses all of the wires together. The heat shrink with adhesive inside forms an excellent water-tight seal around all of the wires.

 

[KneeGrinder]

Originally Posted by 123Saab
Splice by hand if you dont want to use T-Taps.

Like this ! I Approve 100% ! As if that matters....

You may also slip a piece of heat shrink over the gray wire and slide it up the gray wire before the striped away area you spliced into. After you solder, slide the heat shrink down as far as comfortable and shrink it, it won't quite cover the "Y" part of your splice, but it will get the front part where the single gray wire starts the splice connection to where the two wire insulations separate.

" The Front Part of the Splice is More Prone to Moisture as That's the Direction it Will be Forced at the Connection from "

To finish it off, use only 3M Super 33+, or 3M Super 88, and stretch the tape a bit with some tension as that makes it water proof, if you feel like it, put a zip tie at the end of the tape and it will never come undone, and water proof just about for ever!

Now you will just have your usual Ground, bulb, and bulb socket issues that everyone has...lol, good luck, use good materials the first time or you will be doing it again soon.

 

[SwampSurvivor]

Originally Posted by exranger06
Buy these butt connectors:
https://www.amazon.com/gp/product/B07M5WG5KD/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1

Cut the wire where the splice will be, so you have 3 individual wires (1 wire splitting off into 2 wires). Strip about 1/4" insulation off all the wires. Take the two wires that are splitting off and twist them together. Insert the twisted end into one side of the butt connector. Insert the "supply" wire into the other end of the butt connector. Use a heat gun on the butt connector. The solder will flow out and fuses all of the wires together. The heat shrink with adhesive inside forms an excellent water-tight seal around all of the wires.



I saw those earlier. Looks like they would be a good fit. I like the glue/sealant inside to keep corrosion out. I'd have extra heat shrink on top of it and would probably seal with bead sealer ... it appears to just be liquid electrical tape anyway.


Originally Posted by KneeGrinder
Originally Posted by 123Saab
Splice by hand if you dont want to use T-Taps.

Like this ! I Approve 100% ! As if that matters....

You may also slip a piece of heat shrink over the gray wire and slide it up the gray wire before the striped away area you spliced into. After you solder, slide the heat shrink down as far as comfortable and shrink it, it won't quite cover the "Y" part of your splice, but it will get the front part where the single gray wire starts the splice connection to where the two wire insulations separate.

" The Front Part of the Splice is More Prone to Moisture as That's the Direction it Will be Forced at the Connection from "

To finish it off, use only 3M Super 33+, or 3M Super 88, and stretch the tape a bit with some tension as that makes it water proof, if you feel like it, put a zip tie at the end of the tape and it will never come undone, and water proof just about for ever!

Now you will just have your usual Ground, bulb, and bulb socket issues that everyone has...lol, good luck, use good materials the first time or you will be doing it again soon.


I like this method! Seems like a great way to make it an actual harness instead of just a bunch of wires split randomly and run to what they need to be run to.

I have two other trailers. I never took the time to wire them correctly from the start and I have a lot of wiring issues with them. I finally took the time to wire my utility trailer correctly and the dog chewed the tail light and wiring off of the one side. Never ending!

With this trailer, since it's going to be hauling a little more weight than my small utility trailer, I am planning on running dual grounds. I've had excellent luck doing this on my utility trailer the second time around. I will be running a ground wire, attached to the ground wire of the harness I ordered, which will also be connected to multiple points of the trailer frame itself. I figure I should be able to get a few years out of it before I lose all of the grounds

 

[danthaman1980]

Originally Posted by Miller88
Originally Posted by exranger06
Buy these butt connectors:
https://www.amazon.com/gp/product/B07M5WG5KD/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1

Cut the wire where the splice will be, so you have 3 individual wires (1 wire splitting off into 2 wires). Strip about 1/4" insulation off all the wires. Take the two wires that are splitting off and twist them together. Insert the twisted end into one side of the butt connector. Insert the "supply" wire into the other end of the butt connector. Use a heat gun on the butt connector. The solder will flow out and fuses all of the wires together. The heat shrink with adhesive inside forms an excellent water-tight seal around all of the wires.



I saw those earlier. Looks like they would be a good fit. I like the glue/sealant inside to keep corrosion out. I'd have extra heat shrink on top of it and would probably seal with bead sealer ... it appears to just be liquid electrical tape anyway.


Originally Posted by KneeGrinder
Originally Posted by 123Saab
Splice by hand if you dont want to use T-Taps.

Like this ! I Approve 100% ! As if that matters....

You may also slip a piece of heat shrink over the gray wire and slide it up the gray wire before the striped away area you spliced into. After you solder, slide the heat shrink down as far as comfortable and shrink it, it won't quite cover the "Y" part of your splice, but it will get the front part where the single gray wire starts the splice connection to where the two wire insulations separate.

" The Front Part of the Splice is More Prone to Moisture as That's the Direction it Will be Forced at the Connection from "

To finish it off, use only 3M Super 33+, or 3M Super 88, and stretch the tape a bit with some tension as that makes it water proof, if you feel like it, put a zip tie at the end of the tape and it will never come undone, and water proof just about for ever!

Now you will just have your usual Ground, bulb, and bulb socket issues that everyone has...lol, good luck, use good materials the first time or you will be doing it again soon.


I like this method! Seems like a great way to make it an actual harness instead of just a bunch of wires split randomly and run to what they need to be run to.

I have two other trailers. I never took the time to wire them correctly from the start and I have a lot of wiring issues with them. I finally took the time to wire my utility trailer correctly and the dog chewed the tail light and wiring off of the one side. Never ending!

With this trailer, since it's going to be hauling a little more weight than my small utility trailer, I am planning on running dual grounds. I've had excellent luck doing this on my utility trailer the second time around. I will be running a ground wire, attached to the ground wire of the harness I ordered, which will also be connected to multiple points of the trailer frame itself. I figure I should be able to get a few years out of it before I lose all of the grounds

I agree, this is a really good method, as long as you mitigate flexing/bending of the wire where it meets the solder joint. Heat shrink is a great idea, especially if you can push the heat shrink up over the black and gray wires, so about 1" on each side of the exposed wire/solder is covered. Otherwise, tape the two wires together an inch or two up from the solder joint. You want that whole "Y" area to be pretty solid.

Bonus points if you tuck everything into some wire loom when you're done!

Edit: Totally agree on the 3M Super 33+ or Super 88 tape, and the zip tie thing is a great idea!

 

[Linctex]

I have many trailers, some with many (marker) lights.

I actually terminate the connections with a crimp on ring terminal and a stud/nut terminal board!

 

[tom slick]

I use a non-insulated parallel connector for crimping a connection like that if I'm not going to solder.

 

[supton]

Originally Posted by Linctex
I have many trailers, some with many (marker) lights.

I actually terminate the connections with a crimp on ring terminal and a stud/nut terminal board!

That's what I'd call overkill, but I'm sure it makes working on it a snap!