Best and favorite way to splice into OEM wiring harnesses?

[Scar0B2150]

No damage method I used to add power for my 3rd function was to disconnect battery, then disconnect the Molex I wanted source from. I then removed the pin from the Molex connector I wanted to add the Aux wire into. Usually the pin is just crimped to the end of the wire. I open the crimp, solder new wire onto OEM wire, reinsert into the pin and re-crimp(sometimes you can just wire wrap the new wire around the OEM bare wire and solder, saving the step of opening up the crimp). Push the pin back into the Molex plug making sure it locks in. Put some dielectric grease in the back where the wires come out. Plug Molex connectors back together and its done.
To make a 3rd, fourth addition; You can use any of the aforementioned methods using solder or crimp using the new(not OEM) wire. Provided the circuit/wires can handle the draw.
Always use heat-shrink tubing to protect the splice if at all possible.
Do not use the "tap" connectors anywhere they may get damp. But also realize that if used in a dry area the different metal compounds will react to each other and eventually corrode. This is true of all crimp type connections as well, if the metals in them are different from the wire.
So my preferred method is solder and use shrink tube that has "heat activated" glue inside to make it water tight.

 

[mikester]

I'm looking to add lights to my new RTV-XG850. What's your favorite and best way to splice into OEM wires for power? Assume you only have a couple inches of OEM wire to work with.

Anyone who answers with one of these POSs will be automatically ignored:

There is a fused harness with bullet connectors ready to go in the trunk by the steering linkage. No need to splice wires. Splicing wires just means bad connections in the future, I don't recommend doing it if at all possible.

Soldering multi strand wire in high vibration environments isn't a great idea. A good quality crimp tool and good quality crimp connectors is more reliable. I prefer to use existing harnesses instead of tapping in to wires.

 

[s219]

When I added lights to my RTV-X (a diesel) there were existing accessory connectors ready to use under the front hood. They even have their own fuse if I remember right.

For easy splicing where other methods are not feasible I have taken to using these:

3M Scotchlok Electrical IDC (Insulation Displacement Connector) 314-BOX, Pigtail, Self-Stripping, Blue, 22-14 AWG, Pack of 50: Amazon.com: Industrial & Scientific

3M Scotchlok Electrical IDC (Insulation Displacement Connector) 314-BOX, Pigtail, Self-Stripping, Blue, 22-14 AWG, Pack of 50: Amazon.com: Industrial & Scientific

amzn.to

They are filled with a mineral oil sealant to provide water resistant connections.

BTW, in the marine world, solder connections are frowned upon because over time they become brittle due to fatigue from vibration. If I do any soldering on a boat, it's only on connections that can flex without putting stress on the solder joint (for example a splice in the middle of a wire should be OK but soldering a wire to a rigid connector would not).

 

[Bearsixty7]

Surprised no one mentioned liquid electrical tape.
I like a lot of the previous solutions and have used a couple.
However if getting shrink wrap on a wire is difficult, or just any time you want good sealed crimp connector or to coat an exposed wire,
use liquid electrical tape Amazon.com : liquid electrical tape

Even on many crimp butt connectors I will use this to seal it all.

 

[FTG-05]

There is a fused harness with bullet connectors ready to go in the trunk by the steering linkage. No need to splice wires. Splicing wires just means bad connections in the future, I don't recommend doing it if at all possible.

Soldering multi strand wire in high vibration environments isn't a great idea. A good quality crimp tool and good quality crimp connectors is more reliable. I prefer to use existing harnesses instead of tapping in to wires.

On my RTV-XG850, there are tons of fused outlets or connectors under the hood. See the pic below: According to the Kubota tech, every place there is blue tape, there's a fused outlet of some type there.

There are however, two problems here: First is finding one that is powered by the light switch (without of course, taping into the light wiring harness) and the other is finding the compatible plug to fit it.

See, for example, the plug pictured below:

You can see there is a square receptacle plus a bullet connector as mentioned above. The two bottom plugs of the square and the uncovered male bullet connector are grounds. One of the two top plugs is Hot when Key On (as-is the female bullet connector), the other is Hot with the Light Switch. So what I need is the top left plug for my Light Switched on Hot connector.

Here's another example of finding specific connectors to fit the OEM wiring harness:

This is the wiring harness on the rear roll cage; it's for rear-ward facing work lights. Where do you find plugs that will fit this - besides buying the $200 each LED lights from Kubota?

The same connectors are on the front roll bar for a LED light bar:

Thanks for all the suggestions! My Amazon shopping cart is now pretty full!

 

[s219]

Don't feel obligated to use the existing Kubota connectors -- for customization, what matters is the wiring, not the connector on the end. When adding stuff to previous Kubota machines, I removed the pins/wires from the connectors and tied in to them directly.

When adding lights to my RTV-X1120D, I put switches in the three blanks on the dash panel on the left (they take a standard contura-style switch). Three switches were added. One for front light bar, one for rear light bar, and one for flashing orange strobes front/rear. I wanted all of these to be independent of the standard lighting circuit since not all of them are used at the same time.

 

[CoyPatton]

1 correct way without damaging the wire.

strip about 1/2" of the factory wire's insulation off leaving a bare wire exposed without damaging the wire.

take a pin and separate the open strand wire you just striped in half leaving a gap.

strip an inch of insulation off the end of the auxiliary wire. poke it through the gap you made and tightly wrap it around the factory wire.

solder the splice, and wrap it with electrical tape.


you now have a splice that created no damage to the factory wiring.

this is how we were taught In GM training school.

hope i used my best english.

In my opinion, skip the electrical tape and instead use either liquid tape or other sealing material, such as tool dip covering. Otherwise that is a professional splice process, but permanent splice.
You could also locate automotive style moisture resistant connectors that have the silicone inserts to split the circuit.
I do have a question that has not been addressed to this point. Will the circuit you wish to tap into support the increased load?
Do not make the common error or replacing the fuse with a larger rate amperage fuse! This then most likely has changed the safety of the fuse being the weak link in that circuit to the wiring being the weak link! This is a great way to start a fire in your machine!
There are many ways to do this safely.
If you want everything on one switch, consider running the switch wire to energize a relay and run the load off the relay. There are relays available that have a fuse slot built into them and you can match the load wire and fuse size at the relay for the load.

 

[ljjhouser]

I usually solder when I can. But regardless of how I splice, I like to use marine heat shrink because it seals with glue for a water tight connection. I also like the butt connectors shown above with glue and/or solder. I have them, but it is sometimes difficult to add the third wire to the splice. Anyway, I guess any splice that is waterproof, lasts, and looks decent is a good splice. Larry

 

[Tony H]

I'm looking to add lights to my new RTV-XG850. What's your favorite and best way to splice into OEM wires for power? Assume you only have a couple inches of OEM wire to work with.

Anyone who answers with one of these POSs will be automatically ignored:

Insulation displacement connectors, as shown, is never the answer. When there's not enough OEM wire to be able to cut, gather and add the new wire, I take a single edged razor blade, ring around the OEM wire in two spots about 1/2" from each other. With the razor I run from one ring to the other so you can remove that 1/2" of insulation. I twist the new wire to the exposed OEM wire then solder. Since you can't get heatshrink on there, you gotta tape the exposed wire. Soldering makes it reliable

 

[WranglerX]

Here is the comment that is going to upset a lot, soldering produces a rigid brittle joint subject to failure from vibration..... The aircraft and automotive industry has completely gotten away from soldered connection in wiring harnesses.... Yes I agree soldering is probably simplest in cramped space, but mechanical crimped connections "when done properly" is just as good or better ..Unfortunately there is very few options to do proper mechanical "T Tap" (Western Union Splice ) .... No body seems to make a small wire gauge parallel crimp (gutter) tap....

Now comes the rub for many, the 3M parallel taps maligned in first post is probably simples solution, BUT the are a few thing to consider, 1> proper size connector for splice, 2> put a dab of dielectric grease into connector to seal out moisture and oxygen to prevent corrosion before placing wires in connector, 3> be absolutely sure wires are correctly placed in connector then press home connector spade, 4> put zip tie on the main wire and added wire to prevent strain and vibration on connection, ...NO I DONT LIKE THEM EITHER but if done proper they don't fail... The failure of this type of tap is because people don't install them properly (usually takes a pack of 4 to make one connection because of operator failure) ... Like most wiring connections the failure is not in product but is most people don't install them properly....

IF I were to write a resume, it would read something like 38 years in telecommunication industry and have made a million splices from wire sizes for 24 gauge up to 750,000CM.... And in hobby world I do vehicle wiring jobs.... Below is pic of dune buggy wiring project in process (done about 20 years ago, and everything worked first time and NO FAILURES), and still functioning with no problems today...