Joining wires? Crimps/Soldering/Etc

[Jake]

I'm currently fitting Rob Oldham's old engine and wiring loom into my RZS. Some of the loom has been chopped about where folks have robbed the SLD and FCD. So I need to join some wires which have been cut quite close to the ECU terminal blocks. In some cases there are several centimeters of wire missing which I will need to bridge.

 

So, what's the best way to wire in things like speedo converters and Fuel Cut Defenders? I can do soldering but I would prefer to use bullet type connectors if poss because it makes it much easier to remove things later. However, all the crimp type bullet connectors I've tried are rubbish. Half the time they don't seem to get a decent clamp onto the wire.

Some that I got from B&Q wouldn't even fit together, the male part didn't fit into the female connector. OK, it serves me right for buying B&Q stuff but even some expensive crimp connectors I got from somewhere else didn't give me any confidence in the soundness of the connection between the bullet connector and the bare wire.

 

Any tips and/or suggestions? What do the eManage users or other loom hackers use?

[Pete]

I know your problem. Those pesky crimp ends nearly always drop off, right when you've just 'finished' the job and put everything back in place.

I hate them!

 

Soldering all the way for me now.

 

If you're worried about the length of wire coming out of the ECU why not solder some other wire onto that, then use this to crimp onto? At least if gives you a little more flexibility.

[stevie_b]

I use both soldering and crimps (not at the same time!). My soldering skills have come on in leaps and bounds over the past few days whilst fitting a Thor DSC. However, I've also got a set of cheap crimp connectors and crimping tool, which seems to work well. I crunch down on the crimping tool as hard as I can, then give the wire a GENTLE pull (I think most crimps would let go if you gave them a big tug) to make sure the crimp is biting OK.

 

Steve

[eyefi]

do you double up your cable in the bullet?

[Jake]

Do you mean like fold the exposed wire back on itself? I have tried that and it did seem to work a bit better but it still didn't seem perfect.

[Fifty]

Is it true the modern fluxed solders are not so good, and that its best to use the old plumbers flux. I had endless probs wiring in my coil pack clip until my bro used the old stuff then it soldered properly.

crimping didnt work btw

52

[Steviekid]

Soldering all the way for me now.

 

Me too,wouldn't really trust anything else. I used to have an old escort and the previous owner had bodged up putting new speakers in using loads of connectors and it sounded terrible. One day I just rewired the whole lot and soldered it properly and it made a huge difference.

[Jake]

Is it true the modern fluxed solders are not so good, and that its best to use the old plumbers flux. I had endless probs wiring in my coil pack clip until my bro used the old stuff then it soldered properly.

crimping didnt work btw

52

Ah that's interesting. I've been trying to use Draper solder which is 60% tin, 40% lead but it doesn't seem to 'stick' to the wire very well. Do you think I should try some solder with a higher Lead content?

[Pete]

Ah that's interesting. I've been trying to use Draper solder which is 60% tin, 40% lead but it doesn't seem to 'stick' to the wire very well. Do you think I should try some solder with a higher Lead content?

Clean the wire with some spirits first. If the wire is dirty and covered in finger grease it'll never stick properly. Also, heat the wire a little first. (Beware not to damage any close components if too hot)

[Jake]

I've also invented Jake's Famous Hybrid Wire Joining Technique™ (Ver 1.0)

which is where you remove the coloured plastic sleeve , thread it onto the wire, then place the metal part of the crimp onto the exposed wire and solder the two bits together. This seems to provide a sound connection ... until I tried to get the insulating plastic sleeve back over the crimp.

Oh well, 'back to drawing room', as my grandma used to say.

[Pete]

I've also invented Jake's Famous Hybrid Wire Joining Technique™ (Ver 1.0)

I think a few of us already have tried for the trademark on that one Jake!

The wire doesn't usually solder to the metal very well.

[Jake]

Clean the wire with some spirits first. If the wire is dirty and covered in finger grease it'll never stick properly. Also, heat the wire a little first. (Beware not to damage any close components if too hot)

What kind of spirits would be suitable Pete? Like meths or white spirit? How about celulose thinner? I've got gallons of that.

 

...or I think we've still got some Sambuka somwhere

[Jake]

I think a few of us already have tried for the trademark on that one Jake!

The wire doesn't usually solder to the metal very well.

Oh really? Damn, I thought I was being innovative

[Pete]

What kind of spirits would be suitable Pete? Like meths or white spirit? How about celulose thinner? I've got gallons of that.

 

...or I think we've still got some Sambuka somwhere

Just something to get the grease off and clean the wires. To be honest I usually just cut more wire off and start with fresh and not had to clean the wire itself before. Obviously no can do on the wiring loom.

[eyefi]

Do you mean like fold the exposed wire back on itself? I have tried that and it did seem to work a bit better but it still didn't seem perfect.

 

yep.

 

are you crimping on the join, where the connection is made. there is a split in the metal apply the crimp on this join not at 90deg to it.

 

soldering is ok if you are never going to remove it for trouble shooting purposes. i wish i'd never soldered my rltc in now.

 

i always flux the wires then heat them then apply the solder. the flux cleans the wires then the hot clean wires alows the solder to flow into them rather than creating a big blob on top.

[Ian C]

Jake - I've always used solder. Crimping to me is a no-no as I can't bring myself to trust the connection.

 

I used to hate soldering but after all I've done on my car funnily enough I'm pretty good at it now There is definitely a knack to it. You don't need to clean the wires first, and you don't need uncle bob's ye olde solder from 1941.

 

(apologies if any of this is granny-sucking-eggs material, and also if it's completely against what some pro airforce electrician would do but it's what I do and everything I've done so far has only needed to be done once)

 

1) get a good soldering iron - good = "gets hot enough to melt the solder". Mine cost all of £5 and it's brill.

2) get good solder. Vehicle Wiring Products (http://www.vehicle-wiring-products.co.uk/) sells the best solder I've ever used, better than the Maplins stuff.

3) Strip about 1cm of insulation off the ends of each wire you want to splice

4) Twist up the braids of the exposed wire

5) Twist the two exposed ends together in-line. It won't be as stong a mechanical join as twisting them in parallel (wish I had pictures to explain what I meant) but it only has to hold while you solder it and it's much neater than the completed wire coming back 180deg on itself

6) Use the soldering iron to heat up the twisted wires. Touch your solder onto the twisted wires until the solder melts due to the heat *of the wires*. Trying to scoop up solder onto the iron and 'wipe' it onto the wires is doomed to failure and a shite connection.

7) The solder will state-change to liquid once it gets hot anough and will flow by capilliary action amongst the braids. Once this is done, remove solder and iron and allow it to cool

8) Use electrical tape to insulate the exposed wiring. Be sure to stretch the tape as much as possible as you wrap it, otherwise it doesn't stick to itself.

 

 

-Ian

[Ian C]

soldering is ok if you are never going to remove it for trouble shooting purposes. i wish i'd never soldered my rltc in now.

 

 

And can I say "Fields Harness"

 

I'm such a fan of these things. I know that they can seem expensive but now I've got:

E-Manage

RLTC

Apexi AVCr

TRL TSD

AEM O2 sensor module

plumbed into the harness, that's just over 50 (five zero) tapped or intercepted wires. I've plumbed every one of them into a connector plug of some sort so I can unplug everything from the harness and bring it indoors to work on on my desk the thought of putting that lot straight into the stock loom makes me feel ill.

 

-Ian

[eyefi]

And can I say "Fields Harness"

 

yep, i've got a fields (well apexi equivalent) harness, but removing that to troubleshoot one item means removing everything else.

[Pete]

You don't need to clean the wires first, and you don't need uncle bob's ye olde solder from 1941.

It really does depend how dog eared your wire is.

I've seen people try to solder to wires that they've been twisting and playing with for the last 30 mins, or some right dog eared mess which has been around for years. Always strip and use fresh wire were possible and you'll have no worries. I've never had any problem with normal solder.

[Ian C]

It really does depend how dog eared your wire is.

I've seen people try to solder to wires that they've been twisting and playing with for the last 30 mins, or some right dog eared mess which has been around for years. Always strip and use fresh wire were possible and you'll have no worries. I've never had any problem with normal solder.

 

Oh, well, yeah, good point - I'm talking about after cutting off the scrag end and stripping fresh stuff, that was such a given in my universe that I didn't put it in my post, doh. Point 2.5 then - cut the wire back

 

-Ian

[Ian C]

yep, i've got a fields (well apexi equivalent) harness, but removing that to troubleshoot one item means removing everything else.

 

Aye, that's why I've used connectors for everything I can unplug individual items from the fields harness itself. I'll get a piccy of it, it's hilariously complex looking but does make sense Only problem is when a wire is cut rather than tapped but I'll cross that bridge (or indeed, bridge that bridge) if I have to.

 

-Ian

[MONKEYmark]

when i did my thor fuel cut defender i just twisted the 2 wires around themselves to form a lock like tie. never solderd them and taped up well with insulating tape. i did it as a temp thing and was going to solder it but never got round to it. been ok.

 

i have to get a solder gun to build tool collection up. some good tips in here

 

my mate who chips ps2`s up uses a solder iron where you put in temp you want and it holds it at what you set was £150 from farnells

 

dad has one of them portable gas solder irons.

 

got some soldering to do from when i took music out of supra.

[stevie_b]

That was an excellent post Ian. I've learned some stuff from that!

[merckx]

i always flux the wires then heat them then apply the solder. the flux cleans the wires then the hot clean wires alows the solder to flow into them rather than creating a big blob on top.

 

Same here, flux!

 

These bullet connectors are fine if used correctly, I tested one once by puting it in the vice and pulling on the wire. I couln't pull it loose no matter how hard I pulled.

 

The bullet connectors from Maplins push together very snugly.

[Chris Wilson]

In theory all loom wires should be crimped, not soldered. On a proper race car loom there is NO solder used at all, as it embrittles the wires near the solder, and vibration then fractures it. Crimping torace / aircraft loom qulity demands proper crimps and a proper crimping tool, that often only works with one size / make / style of crimp. the Motec recomended crimp tool is over 280 quid.

 

Having said all that soldering is fine, and infinitely superior to the automaotive spares shop type of crimps and crimp tool, and far better than those dreadful Scotch Locks. I use soldered joints on my road car, but the race car has always had the luxury of a professional loom and connectors. A "proper" aircraft quaity loom is joy to see and use, but VERY expensive.