Correct way to splice one wire into another

Correct way to splice one wire into another

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Discussion

Salgar

Original Poster:

3,283 posts

184 months

Wednesday 9th March 2011
quotequote all
I've read many times about how using 'vampire' clips is horrible and evil and ohnoneverdoit.

However I've never seen a good explanation about a good way of doing it.

e.g. I have some new component I want to connect up to the ground and power wire that currently connects to my cigarette lighter. Would the correct way be to cut the wire and somehow solder all 3 together, or is there some electronic component that can connect 3 wires in a way that isn't evil?

EDLT

15,421 posts

206 months

Wednesday 9th March 2011
quotequote all
Vampire clips can give bad connections, soldering the wires together would be a better idea.

Eggman

1,253 posts

211 months

Wednesday 9th March 2011
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I'd probably go for for an appropriately sized piggyback spade connector and be careful about insulating it properly. To avoid clutter, I'd most likely make my own earth by putting a crimp ring connector behind a screw somewhere on the bodywork.

Ozzie Osmond

21,189 posts

246 months

Wednesday 9th March 2011
quotequote all
You can,
a. use a sharp knife to strip away about 1 cm of insulation from your existing wires WITHOUT cutting or damaging the metal conductor inside.
b. Expose about 1 cm of metal conductor at the end of the wire you want to attach.
c. Then twist the exposed wire you want to attach (b) around the exposed section of wire (a).
d. Melt solder into the join for a permanent connection.
e. Bind the whole lot tightly with insulating tape.

Don't forget to fit a fuse! the cigarett lighter circuit has a very big fuse which won't protect anything remotely delicate. Fit another smaller current fuse "in line" with your added accessory.

BliarOut

72,857 posts

239 months

Wednesday 9th March 2011
quotequote all
Piggyback spade connector?

grimfandango

372 posts

185 months

Thursday 10th March 2011
quotequote all
Salgar said:
I've read many times about how using 'vampire' clips is horrible and evil and ohnoneverdoit.

However I've never seen a good explanation about a good way of doing it.
Theyre not that bad really wink I've had a few kit cars and you get loads of these things. I've had just as much trouble with piggyback spade connectors and the connectors where you crimp multiple wires together.
It seems to be more about who did the job (and the quality of it) rather than the type of connector used

whatever you use just make sure you do it proppely wink and if it were me I'd just get on and do it with the vampire conector, just make sure you use the right size and squash it up nice and tight with some pliers. smile

WeirdNeville

5,962 posts

215 months

Thursday 10th March 2011
quotequote all
Ozzie Osmond said:
You can,
a. use a sharp knife to strip away about 1 cm of insulation from your existing wires WITHOUT cutting or damaging the metal conductor inside.
b. Expose about 1 cm of metal conductor at the end of the wire you want to attach.
c. Then twist the exposed wire you want to attach (b) around the exposed section of wire (a).
d. Melt solder into the join for a permanent connection.
e. Bind the whole lot tightly with insulating tape.

Don't forget to fit a fuse! the cigarett lighter circuit has a very big fuse which won't protect anything remotely delicate. Fit another smaller current fuse "in line" with your added accessory.
This is the best way to do it, makes a good permenent connection.
Make a loop with the end you're joining, twist it round the exposed wire and back onto itself, then make a neat solder joint flowing the solder into the splice.

Man from UNCLE

3,762 posts

218 months

Thursday 10th March 2011
quotequote all
Vampire? Do you mean scotch lock? If so I don't lick them either, neither do I like the crimp type spades & have had problems with both. I would go with Ozzie Osmond's choice but use shrink wrap instead of insulating tape. I will use crimp spades but will solder them & use shrink wrap on those as well.

shalmaneser

5,934 posts

195 months

Thursday 10th March 2011
quotequote all
Ozzie Osmond said:
You can,
a. use a sharp knife to strip away about 1 cm of insulation from your existing wires WITHOUT cutting or damaging the metal conductor inside.
b. Expose about 1 cm of metal conductor at the end of the wire you want to attach.
c. Then twist the exposed wire you want to attach (b) around the exposed section of wire (a).
d. Melt solder into the join for a permanent connection.
e. Bind the whole lot tightly with insulating tape.you should really use shrink-wrap

Don't forget to fit a fuse! the cigarett lighter circuit has a very big fuse which won't protect anything remotely delicate. Fit another smaller current fuse "in line" with your added accessory.
This is the correct method.

Cooky

4,955 posts

237 months

Thursday 10th March 2011
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Ozzie Osmond said:
sensible stuff

XanderH

46 posts

165 months

Thursday 10th March 2011
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When did we start calling Scotchlocks, 'Vampire Clips' then?

Steve H

5,288 posts

195 months

Thursday 10th March 2011
quotequote all
Scotchlocks are rubbish and allow moisture in as well as weakening the wire, not a nice way to do it.

Soldering is OK but you can have issues on cars where vibration and movement can cause the joint to fail where the solder ends.

Wherever possible now I'm using heatshrinkable crimp connectors like LIKE THESE. They are easy to use , strong and well sealed against corrosion.

mk1matt

405 posts

165 months

Thursday 10th March 2011
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shalmaneser said:
you should really use shrink-wrap
But how do you get the shrink wrap onto the wire in the first place if you've not cut it? I'm guessing he's not suggetsing electrical tape is better than shrink wrap in normal use, but unless you cut the wire, sometimes tape is the only way to go.

acf8181

797 posts

234 months

Thursday 10th March 2011
quotequote all
Steve H said:
Scotchlocks are rubbish and allow moisture in as well as weakening the wire, not a nice way to do it.

Soldering is OK but you can have issues on cars where vibration and movement can cause the joint to fail where the solder ends.

Wherever possible now I'm using heatshrinkable crimp connectors like LIKE THESE. They are easy to use , strong and well sealed against corrosion.
+1 (and i'm a wiring harness technician for a supplier of f1 teams)

We use fancier and more expensive splices like these - http://www.ttiinc.com/object/fp_tyco_raychemminise... - but those in the above link are fine for road use

BadgerBill

274 posts

239 months

Thursday 10th March 2011
quotequote all
I tend to slip a bit o' heatshrink over one wire, strip the wires back 5mm then just push them together like you might do with your fingers, sort-of interlocking, then solder that. slip the heatshrink over the top and do it's thing.

Unless you are leaving it under water or hanging stuff off it, there is very little chance of failure.

BB

HellDiver

5,708 posts

182 months

Thursday 10th March 2011
quotequote all
Scotchlocks work fine IF you use the correct size connector for the cable you're using. Too thin a cable for the Scotchlock makes dodgy connections.

defblade

7,435 posts

213 months

Thursday 10th March 2011
quotequote all
I like the "choclocate blocks" (the ones with 2 screws in the top). Mustn't try and force too many wires into 1 block, and should trim the wires long enough so they're held down by both screws. Then wrapped in insulating tape to provide insulation and mechanical support (as for all connections - they will tend to flex at the point the insulation ends and the wire is exposed so that section should be supported).

I've never had any problems with these, done as above (including a couple of years' rallying smile ).

munroman

1,831 posts

184 months

Thursday 10th March 2011
quotequote all
defblade said:
I like the "choclocate blocks" (the ones with 2 screws in the top). Mustn't try and force too many wires into 1 block, and should trim the wires long enough so they're held down by both screws. Then wrapped in insulating tape to provide insulation and mechanical support (as for all connections - they will tend to flex at the point the insulation ends and the wire is exposed so that section should be supported).

I've never had any problems with these, done as above (including a couple of years' rallying smile ).
For best results with these you should 'tin' the ends of the wires with solder, as the copper tends to flow away from the screw under pressure.

We had awful problems with a new production machine cutting out, it turned out the supplier hadn't done this to the wiring, and 84 out of 120 connections were loose in some way!

defblade

7,435 posts

213 months

Thursday 10th March 2011
quotequote all
munroman said:
For best results with these you should 'tin' the ends of the wires with solder, as the copper tends to flow away from the screw under pressure.
I did miss "give the wires a little tug, to check they've caught". I would also say, thinner wires I double over, too.

Mr2Mike

20,143 posts

255 months

Thursday 10th March 2011
quotequote all
Even used "properly", Scotch locks are thoroughly nasty things IMO.

If you use decent automatic wire strippers you don't have to faff around with a knife cutting the insulation, the strippers will cut it and pull the insulation back leaving a perfect, undamaged section of bare copper. Wrap the wire to be spliced around it, solder and insulate. In cases where you can't use heatshrink, use decent brand insulation tape and make sure you stretch it around the joint and provide a generous overlap at each end of the splice to support the wire and prevent flexing near the soldered area.