(01-30-2026, 04:22 PM)LoneRyder Wrote: Hi everyone, I wanted to learn how to fuse, connect, or solder two U7 LED headlights into a 1-to-2 Y-splitter. Below are some pics of what they look like. I have an electric kick scooter, and one of the front headlights has blown out. So I am planning to buy two (2) new sets of U7 headlights and a Y-splitter.
My idea was to cut off the ends of the 2 female Y-splitters and solder the wires to the U7 headlights. (If I can avoid cutting the heads and just pull the pins out, that would be great). But if there are better methods, such as attaching heat-shrink butt connectors or solder paste, etc., I would rather take the advice of the experts in the group.
I have never done this before, so before I do, I want to know the best ways to do it and whether anyone has a step-by-step instructional guide or videos of the process, please lmk.
@LoneRyder
The proper method would be to get two 3 pin male connectors to mate with female connectors of the Y harness. You might find connectors that have extractable pins or fixed pins. You technically need extractor and insertion tools for first type, but if you know what you are doing the work can be done without them (the tools are low cost and prevent potential damage). I would crimp and solder the pins (low temp solder, need some flux also, 25W iron). Before soldering or crimping always clean the wire (ink pen eraser works great) to remove any insulation coating (not always apparent to the eye) and wipe clean with alcohol (70% or higher). Soldering prevents corrosion, whereas the crimping only method allows moisture intrusion at the wire to pin interface. Depending on the connector type you may find it best to add silicone self-vulcanizing tape or heat shrink on the wire before sliding the boot/cover into place (check for clearance). Add enough to take up any excess space between wire and boot. That also acts as a stress relief at the pin connection and at the external area past the boot (some boots will have a stress relief extension some do not, but it will not seal out moisture). You can determine how much heat shrink extends outward depending on your routing of the connected harness and flexibility you require. You can also add heat shrink over that entire assy or forego the internal heat shrink and just do it all externally. The problem with that method is that the heat shrink needs to be wide enough to get over the connector body and also shrink down to seal the wire which it might not do adequately (do not overheat the shrink in trying for a tighter fit!).. You can add silicone tape to build up the wire diameter so that the wider heat shrink will close tightly on the wire and seal it. I highly recommend adding a dielectric paste (silicone) inside the connector hollow area and at all pin conjunctions. Use silicone tape under heat shrink at external areas to prevent moisture intrusion and corrosion. If you are making it a more permanent set up where you are not concerned about disconnecting then just wrap with a layer of silicone tape and heat shrink over the entire assy once connectors are joined.
I would do the same procedure at the single connector end. Use a female connector to insert into the male harness end.
Note: crimping is quick and essentially requires no special tools (though technically the proper ceimper should be used. Crimping only is fine for stable connections that are bouncing around with loose wires. I have worked professionally on multi-pin connectors having dozens of pins per connector and crimping works fine, but I was dealing with 1" or larger cables with bayonet locking onto hardware and no chance of moisture exposure. Also, if using extractor and insertion tools with pins in rubber surround within the connector housing rubbing alcohol acts as a lubricant and makes insertion and extraction a little easier (I highly doubt you wi have that type of connector). Do not use tape as suggested (I assume electrical tape; but if silicone tape it should have heat shrink over it); it is amateur, only marginally water resistant, and very temporary. If you have done the job correctly you will not need it.
Amateur method: even if you end up cutting wires the procedure is essentially the same. Clean wire ends, wipe with alcohol, flux, solder, silicone wrap, heat shrink.
Temporary and very poor method: twist bare wire ends together and electrical tape. Suggested as a method if you need to determine routing before doing it properly once you know where everything will be mounted and wiring routed.
Regardless of method, DO NOT CUT OFF EXCESS WIRE UNTIL YOU KNOW EXACTLY HOW THINGS ARE GOING TO BE IN THE END. Even then it is best to leave a little excess. Ensure there is enough wire to account for pivoting, movement, removal of parts for maintenance, charging, etc. (steering, suspension, battery, etc.).
Hope that helps.
Good luck!
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