What's your preference on the above? I have a 6 volt harness to re manufacture that has a combination of both, poorly executed. I hate the look of the hard coloured plastic sleeves of the crimped joints, especially on old British re built bikes, makes a harness look tacky to my eye. I know the aircraft industry uses crimped joints but the specification of that equipment must be of a far higher standard than is available over the counter. Am tempted to solder all joints unless some one can point me in the direction of a reasonable crimping tool and some neater crimps that make a tight secure joint. Will any crimping tool work with any crimp or is that where the mistake is made?  John

The following variables apply:
1. try to use high quality wiring, connectors and tools (crimpers, soldering iron, solder);
2. Your technique is important - if your soldering work is poor then things tend to fail. If your crimping technique is poor then wires tend to pull out from connectors.
3. My work tends to improve with practise. I generally use crimping with best quality crimpers on the basis of what the aviation industry does. A good quality crimper is a once in a lifetime purchase... consider the cost of rescue if you break down due to a wiring failure.
4. Consider getting high quality connectors such as weather pack rather than basic ones, particularly if wiring is at risk of corrosion. They will repay the effort in terms of reliability.
5. The product deOxit is brilliant for cleaning and maintaining wiring and connectors. If in Australia, JayCar carry it.
Hope this helps.

This same topic was recently discussed extensively in a thread on EEVBlog.  There were arguments for and against the use of crimps over solder in that thread.  It is recognized that crimped connections are best in a vibration-proned environment like automotive and aircraft but the quality of the joint plays a paramount role.  You have to make an airtight crimp with no compromise of the wire strands or insulation and this takes professional tools to accomplish.  Crimps made by tools available to the home enthusiast don't measure up.  Soldering will improve the quality of the electrical connection but there are high risks of wire fatigue and resulting joint failure at the point where the solder gets wicked up into the strands.

For insulated connector crimps, I use a high quality ratchet crimping tool.  For un-insulated crimps, I use a standard set of crimping pliers but of the highest quality I can afford, like Engineer PA-09 or PA-20 Micro Connector Crimpers.  If I want extra security of the connection, I will solder it but I am careful to limit the amount of solder used and to avoid wicking into the strands. That means I limit the soldering to the area where the wire ends exit the crimp. I don't solder insulated connectors.

Most important is to get the right crimping tool and a quality tool. I do use the coloured insulated type sometimes but NEVER in a situation where water can get to it. For making a complete harness I use the multi pin block connectors in 2.8mm or 6.4mm depending on current.I cant find them ATM but aliexpress have sellers that do bulk deals in these type of connectors.
I bought a pack of varying sizes 9, 6, 4, 3, and 2 pin types some time ago. you can get them in quite a few different colours of the plastic block. I will have a better look later and try to find them.
I have built 2 new harnesses for older Jap bikes recently and will need some more stock soon for myself.
If you want to get heaps of various colours of wires go to a wrecker and buy a few car wiring harnesses and strip them out.

I find the anguish over connectors and crimping tools rather amusing when dealing with bare copper wire.  If you want quality, the first thing you need is tinned wire.  That is not to be found in our harnesses.

Rick:

https://www.ebay.co.uk/itm/40-Set-Motorcycle-Car-Electrical-2-8mm-2-3-4-6-Pin-Wire-Auto-Connectors-Terminal/272967577631?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m2749.l2649.

They're in Shanghai, so I suspect a hunt on ebay.au or AliExpress will turn them up.

Everything that needs to be said about crimps has been said above , so I'm just going to add a few comments about connectors.

I use Molex '93-thou series' connectors in 2, 3, 4, 6, 9, 12 and 15-way. These are the round-pin OEM fitment to most Japanese and European bikes from the mid-Eighties through to somewhen about now. For bullet connectors when needed, I use Japanese bullet connectors

http://www.vehicle-wiring-products.eu/section.php/175/1/japanese-motorcycle-bullet-socket-connectors

For wiring, I use thinwall cable

http://www.vehicle-wiring-products.eu/section.php/198/1/single-core-pvc-thin-wall-cable

For harness/loom covering I use PVC tubing - I hate tape of any type. The downside is that it takes very careful planning to run wires through the tubing to where you need them, particularly when a number of wires go off in different directions. Any soldered wiring joints I cover with heatshrink tubing.

[Edit] See post 20 here: https://www.k100-forum.com/t10428-comberjohn-s-ghost

I'm also seeing a lot more bikes equipped with 'Superseal' waterproof connectors; very expensive and very effective. I use these when building new looms for a UK sidecar company.

I never use pre-insulated connectors of any type.

As for those yellow, red and blue pre-insulated -things-; damn devil's spawn is what they are

Point-Seven-Five: Using marine-grade (tinned) wire on a bike is complete and utter overkill and quality does depend on your tools as well as your materials.

This is what I was talking about but a much bigger kit.
https://www.aliexpress.com/item/2-8mm-2-3-4-6-Pin-Electrical-Wire-Connectors-Spade-Terminals-Kit/32838745444.html?spm=2114.search0104.3.208.mBh6Fv&ws_ab_test=searchweb0_0,searchweb201602_4_10152_10065_5000015_10151_10344_10068_10130_10342_10547_10343_51102_10340_10341_10548_5130015_10084_10083_10307_10131_10132_10133_10312_10059_10313_10314_10534_5790011_100031_10604_10103_10605_10594_5060015_10142,searchweb201603_6,ppcSwitch_5&algo_expid=fbead1a1-04ac-47ba-b25b-2d6390be334c-32&algo_pvid=fbead1a1-04ac-47ba-b25b-2d6390be334c&rmStoreLevelAB=5

Bit cheaper than the ones I bought!

Dai wrote:Bit cheaper than the ones I bought!

because they are not the same , just another counterfeit copy of something with a reputation already established by the hard work of others ...

...or didn't pass the QA test because the molding wasn't quite up to snuff. Even my much-favoured Molex connectors are made in China these days.

JGT wrote:What's your preference on the above? I have a 6 volt harness to re manufacture that has a combination of both, poorly executed. I hate the look of the hard coloured plastic sleeves of the crimped joints, especially on old British re built bikes, makes a harness look tacky to my eye. I know the aircraft industry uses crimped joints but the specification of that equipment must be of a far higher standard than is available over the counter. Am tempted to solder all joints unless some one can point me in the direction of a reasonable crimping tool and some neater crimps that make a tight secure joint. Will any crimping tool work with any crimp or is that where the mistake is made?  John

I do not like the plastic coloured sleeves either, I went online to http://www.vehicle-wiring-products.eu
They do different types of crimped connectors, even the Japanese 3.5mm type, they come with clear plastic sleeves. A decent crimping tool is also a must, no problems so far.

I work for a BMW dealership (automotive).  Our techs are not allowed to solder any wiring repairs - ONLY crimp with ratchet pliers.  FWIW, these pliers cost the dealership something like $300+

I use a set of Matco crimping pliers with BMW crimp connectors.  The BMW crimp connectors for smaller wire (<18ga) are so small they fit through the thinnest heat shrink tubing and when done right, are barely any thicker than the original wire and fit in harnesses just fine.

I find that with cheap crimping pliers, the key is having parallel jaw movement, not scissor movement.

boostd4 wrote:Our techs are not allowed to solder any wiring repairs - ONLY crimp with ratchet pliers.  FWIW, these pliers cost the dealership something like $300+

Pressure-calibrated before they leave the factory to ensure that every crimp is identical. The price looks about right - I've been (very) briefly tempted on a few occasions to buy a Molex calibrated crimp tool but that really would have been bragging-rights over practicality.