Board logo

Splicing into wire advice
number-1 - 12/8/21 at 04:39 PM

This may be personal choice based, but, im after the best way to splice 1 wire into an existing length of wire...but mid length. It will be open to the elements due to the location of it



1- remove a section of insulation, add and solder the new wire then wrap in tape

2- cut the existing wire in the middle, cut back 5mm each end then slide over heat shrink for later use, before soldering the 3 wires together then heatshrink over the top

3 As above but use the half barrel crimps as they use in bike looms, then heat shrink

4 As number 2 but use those easy solder tubes that you heat, the solder melts and seals at each end

Any other ideas welcome exept the scotch lock things

N1

[Edited on 12/8/21 by number-1]


40inches - 12/8/21 at 04:47 PM

I have used no 4 many times. So far so good
Although with any crimp connectors, I always strip the wire to go completely through the connector.


myke pocock - 12/8/21 at 11:09 PM

If I am splicing or joining wires I have always used self amalgamating tape rather than simple insulating tape.


Theshed - 13/8/21 at 07:12 AM

The sniffy response is that it is unwise to solder automotive wiring and that a good crimp is the only acceptable way to go. In real life a soldered joint is probably better than a bad crimp (cheap connectors and a pair of pliers). If exposed to the elements I would worry more about how to protect the joint than whether it will fail but the two are interrelated. Use a good adhesive heat shrink both to protect and to support the joint and the chances are that you will never have any issues.


nick205 - 13/8/21 at 10:02 AM

If there's enough slack in the wire to be spliced into I cut that wire then strip a few mm of insulation off each side of the cut wire + the end of the wire being joined in. The crimp the 2 wires together and adhesive eatshrink over the crimp for some added mechanical + sealing properties.

I'm with "Theshed" and prefer to avoid soldered wire joints in automotive applications. Soldered joints don't like vibration (risk of cracking and failure). OEM wiring looms avoid solder joints for this reason.

I'm also with "myke pocock" and avoid insulating tape in favour of self alamgamating tape or better still loom tape (loom tape lets you back in for future mods & repairs).


40inches - 13/8/21 at 10:54 AM

These are the connectors the OP was referring to, they solder, grip and waterproof the joint.
LINK


Mr Whippy - 13/8/21 at 12:07 PM

quote:
Originally posted by 40inches
These are the connectors the OP was referring to, they solder, grip and waterproof the joint.
LINK



Haven't seen them before, they look great

Over the years I've only ever had rotten wire (black wires) & connector corrosion issues (stupid bullet ones being the worst) never a broken solder joint. These by keeping moisture out should last way longer than the car.




[Edited on 13/8/21 by Mr Whippy]


coyoteboy - 13/8/21 at 12:58 PM

https://workmanship.nasa.gov/lib/insp/2%20books/links/sections/407%20Splices.html


number-1 - 13/8/21 at 04:29 PM

Cheers for the replies chaps. I have seen the barrel crimps used in bike looms and wondered why they didnt solder but as Theshed stated, the solders dont like vibration. Plus my soldering isnt the greatest so could be a safe route


gremlin1234 - 13/8/21 at 05:42 PM

quote:
Originally posted by myke pocock
If I am splicing or joining wires I have always used self amalgamating tape rather than simple insulating tape.


absolutely agree with this, plain insulation tape can be horrid. especially when subjected to under bonnet conditions.

I would use self amalgamating tape, or heat shrink.


craig1410 - 13/8/21 at 11:42 PM

I'd go with option 4 every time.

After I graduated as an electronics engineer, my first job was with Lucas Automotive Electronics where I ended up working in a department designing engine test harness looms for early diesel common rail engines. These looms were built to aerospace standards with very expensive connectors and we always used those adhesive-lined heatshrink, pre-loaded solder connections. These were covered in additional layers of adhesive lined heatshrink sleeving to form the Y junctions and were encapsulated in braided sleeving as well. There should be no issues with vibration harming the solder joints when encapsulated properly because the solder is not being flexed or fatigued.

HTH


spiderman - 14/8/21 at 03:35 PM

quote:
Originally posted by 40inches
These are the connectors the OP was referring to, they solder, grip and waterproof the joint.
LINK


I've used those on installations in military vehicles, they are excellent. An other tip is if you buy heat shrink get the adhesive lined version it keeps the environment out and adds mechanical strength to cables at their most stressed points.