Good electrical connections are an extremely important factor in the reliability and durability of accessory installations on motorcycles – and therefore connections are a common source of faults on GoldWings which have had them installed. The accessories or display lighting units themselves can of course be a source of unreliability too, but poor connections account for lots of failures.

The plugs and sockets which come with ready-to-use kits will usually, but not always, provide reliable connections but otherwise the installer has to make up the connections.  This Part of the Series tells you how best to do this.

Connections on a motorcycle are often exposed to fairly harsh environmental conditions and at the very least they are likely to get damp if not completely wet.  Motorcycle connections are also, even on a GoldWing, subject to vibration.

A wide variety of cable connectors and terminators are sold commercially, so there’s no shortage of choice.  Each different type of connector has special advantages of one sort or another, which is why there are so many different types sold.

Some are specially designed for quick and easy application, maybe even without tools, but they may not be suitable for the motorcycle environment and as a general rule the robustness and durability of crimped connectors is to be preferred.

Making connection to switches usually involves soldering.  Since the switches are sometimes installed in an exposed position (eg on the handlebars) the connections often need protection, for example by enclosing in heat shrink sleeving.

Service connections are made in cable runs to allow disconnection when the bike is being dismantled for servicing or repair in order to avoid having to cut the cables.  Male/female multipin connectors are available in a wide range of types and sizes and can be suitable for this purpose, especially when there are several cables running together (i.e. a wiring loom) because they help to ensure the cables are reconnected again correctly.  That is of course why motorcycle manufacturers use them; GoldWings have lots of them. For a service connection in a single or two core run of cable a simpler approach is possible and “bullet” crimp connectors can be used.

If you are installing wiring looms for accessories and display lighting on a GoldWing you are more than likely to need service connections in your cable runs too.

Wires and cables, cables and looms

It’s worth explaining just a little bit of terminology, so we know what we’re talking about.

We all speak of “wiring up” accessories but strictly speaking we don’t use wires on a bike at all; they are, technically speaking, cables.

Wires are no good at all on bikes.  They are single strand electrical conductors, such as are commonly used in domestic “wiring” and also to make connections inside electronic devices, for example to make connections on a printed circuit board.   Wires, because they have only a single strand, are not very good at being flexible or tolerating being bent back and forth or vibrated, which will cause them to snap.  Hence they are no use at all on a bike.

Cables are made from multiple strands of fine wire, which makes them flexible and therefore better able to cope with vibration.  So we always use cables rather than single strand wire on motorcycles.  If “wiring” is mentioned anywhere in this Series of articles take it to mean cabling.

Cables for automotive use always have a sleeve of plastic insulation around them and sometimes two or more “cores” of cable are grouped together within another, outer layer of insulation – so called “multi-core” cables.

Looms are groups of cables held together.  It’s often necessary to group cables together as they are routed around a motorcycle and these groups are referred to as “wiring looms” or just “looms”.  They are held together as a loom in various ways:

1. Enclosing in tough plastic sleeving, as Honda does at manuafacture (the cables have to be threaded through it before terminals are attached).
2. Enclosing in Heat Shrink Tubing (as above but the sleeving can be shrunk to fit closely around the loom afterwards)
3. Binding with insulation tape (often done at each end of plastic sleeving too, for reinfoircement)
4. Binding in Spiral Wrap (cables don’t need threading through so it can be used anytime)
5. Held together (and maybe also to the bike’s structure) by cable ties

Butt Joints are end-to-end joints which join one cable to another.

Splice Joints are when one cable end is jointed to another cable somewhere along its length, i.e. to form a branch connection.

Terminal joints are made between the end of a cable and a metal fitting (of various types, eg a ring fitting or a 6.3mm female push-on connector) which can then be used to connect to another terminal fitting, such as the GoldWing’s Accessory Terminals or the 6.3mm blade connector on a relay.  (If you want to impress a professional Auto-Electrician with your knowledge, the proper name for a ring terminal fitting is a Ring Tong Tag!)

Service Connections are included in wiring looms to allow easy disconnection and reliable reconnection when the bike has to be dismantled for servicing or repair.

Precision wire strippers, cheap and easy to use

Baring cable ends for jointing

For standard crimp joints you will usually need to strip about 5mm of insulation from the end of the cable, but slightly more than this if you plan to insert two or more cables into the same crimp tube.  (You then twist them together and trim the bundle of bared ends to 5 mm.)

One professional Electrician I know pours scorn on the use of wire stripping tools and will use ever only side cutters to bare cable ends, but he’s an obsessional individual of an older generation.  Applying just the right amount squeeze to get side cutters to nip and weaken the insulation so you can pull the end bit off (without also damaging the cable) is a considerable knack.  I find it easier and much more reliable to use wire strippers; they are not expensive and they allow you to bare cable ends consistently and reliably – so why make life difficult?

Simple wire stripping pliers such as those illustrated provide for various sizes of cable and the jaws are usually labelled with the sizes, so they can also act as a wire gauge. You will get the hang of the “feel” of correct stripping, when they cut far enough through the insulation to allow you to pull the insulation off with a sideways tug; don’t use jaws which are too small because you will damage the wires.  If in doubt try cutting jaws which are too large before resorting to smaller ones; you can’t do it the other way around.

Other types of wire strippers are available which are handy for removing the outer insulation of multicore cables without harming the inner layers of insulation, a task which is otherwise much more fiddly and time consuming to do with a knife.  However this type is expensive and for the DIY biker are perhaps an unnecessary extravagance because a knife will do the job perfectly satisfactorily.

Jointing Methods – Solder, crimp, screws or insulation-displacement?

The way in which a connector or terminal (or another cable) makes its electrical contact with a cable is important on motorcycles, because of the risk of dampness (and therefore corrosion) and vibration.

The options are soldering, crimping, screws which compress the cable and so-called quick splices, eg Scotchloks, which make a connection by displacing the insulation around a cable, i.e. a blade a bit like a guillotine with a slot in it makes a nick in the plastic covering of the cable.

Soldering, if done  properly, provides a reliable electrical connection.

Solder is metal alloy (predominantly tin) which has a low melting point.  the type used for our purposes is flux-core solder, which is supplied in wire form and contains and inner core of flux (cleaning agent) which prepares the cable (and/or terminal fitting) to make a bond with the solder.

Insulated cable which is to be joined by soldering has to be “bared” at the end, i.e. to have a short length of insulation stripped from it.  Melted solder flows onto the heated cable end (or fitting) covering its surface intimately and, as soon as the heat source is removed, quickly solidifies to form a permanent covering.

Each item to be joined is first “tinned”by applying solder to it separately.  The two pieces which are to be joined are then brought together and joined by touching both of them with the soldering iron while, if necessary, applying more solder.

The key to successful soldering is to have the right amount of heat available for transfer when the hot soldering iron is touched against the work-piece, enough to allow it to melt the solder which i also being touched against it but not so much as, for example, to damage the insulation further along the cable.  This involves choosing the right size of tip for the soldering iron as well as heating the iron to the correct temperature.  For thin cable you need a small tip, for thicker cable a bigger one, the idea being that the tip is capable of transferring enough heat instantly it’s touched against the work-piece for the work-piece to become hot enough to melt the solder which is placed against it at the same time.  So it’s the heated work-piece which melts the solder on to itself rather than the soldering iron.

There are limitations and disadvantages to soldering, not least that soldering joints take time and skill to make and they also need insulating afterwards, usually either by wrapping with insulation tape or by using heat shrink tubing.  (Heat shrink tubing is extremely useful when installing electrical accessories and display lighting, so more about that later.)  “Wicking” along the length of the cable is also to be guarded against; if too much solder is used and the cable is heated too much the molten solder will creep along the cable under the insulation by capillary action; this will stiffen the cable undesirably and may also damage its insulation.

Soldered joints are often necessary to attach cables to switches and they can also be useful for making butt joints (end-to-end cable joints) in confined spaces such as inside switch housings.  Also when it’s important to avoid increasing the thickness of the cable unnecessarily, for example when extending the length of a cable which has to be routed through narrow spaces or along a tortuous path, such as from the handlebars, around the steering head and inside the fairing.

Soldering carries risks of collateral damage or burning if it’s done on the bike because it involves a hot soldering iron.  But it isn’t all that difficult to get the hang of making simple soldered joints and you can always practise on the bench before trying anything closer to the bike.

As with most jobs it helps to have the proper tools.  Mains powered soldering irons are available which have various sizes of exchangeable tips  and also automatically heat the iron to the correct temperature and hold it there, which make life a lot easier.

You can, if necessary, take soldered joints apart and then re-make them without having to shorten the cable.

Crimped joints are made by inserting the bared end of a cable into a metal tube which is then deformed, i.e. crushed, around it to grip it firmly.  The metal used for these terminals (in the better ones it’s copper with tin plating) doesn’t spring back open, so once it’s crushed it’s crushed and the joint with the cable is permanent. For auto-electrical work, including on motorcycles, the metal tube is always supplied with a plastic sleeve around it which can stand up to being crimped and still provide effective insulation afterwards.

The plastic sleeves in three colours: red, blue and yellow which are small medium and large sizes of cable respectively.  You can crimp two or more small cables into a larger size connector if necessary to make splicing and branching connections.

Crimp tube are sold as straight lengths of tube (“butt” joints) into which cable can be inserted from both ends to make an end-to-end connection, and they are also sold as terminals, when the metal tube is attached to a fitting (such as a ring) which can be used to connect to screw terminals.  A wide range of these terminal crimp fittings is available.

Crimped joints are permanent and they cannot be opened up and and then remade.  To remake a crimped joint it is necessary to cut the cable and make a new joint with a new crimp tube and therefore the cable has to be shortened slightly, although usually only by 5 mm or so.  Some people try to re-open a crimped joint by squeezing the tube open with a pair of pliers but this is bad practice.  Even if you can release the pressure on the cable to get it out without cutting it, the cable is likely to have suffered damage and using it without cutting off the end and making another, replacement joint with a fresh fitting is to risk an unreliable connection.

Screw-fixed (Strip) connectors are metal tubes enclosed within nylon or PVC insulators, each tube having a pairs of screws threaded into their sides so that they can be tightened up to grip a bared cable which is inserted into it.

Each element of the strip is a separate connector, insulated from the next one and so several of them could be used to make a multi-core connection.  They can also be unscrewed, so joints can be undone and remade more or less without limitation.  You can also cut off as many or few connectors as you need from the strip with a knife.  These connectors are also cheap to buy.

However a long strip takes up a lot of space and above all they’re unreliable on a vibrating motorcycle and they tend to look a mess.

Don’t resort to this type of connector except maybe temporarily, as part of a test installation.

Insulation-displacement joints (eg Scotchloks) are made by inserting non-bared cable into a tubular space in a plastic hinged device which is then closed around it.  A metal slider, like a guillotine with a slot in it, can then be forced down on to the cable “displacing” insulation on either side of it so it makes electrical contact with the conductor inside.  It is not necessary to bare the cable end and indeed the device can be fitted around a cable anywhere along its length in order to make a connection with another cable inserted into another tube in the fitting. The “guillotine” makes the connection between the two cables when it is pushed down into position inside the plastic housing, where it remains.

Although on the face of it these connectors are potentially very useful in auto-electrical work, especially if you need to splice a cable into an existing cable run because they allow you to do so without actually cutting the existing cable.  Inside cars they may have a role but on motorcycles they are unreliable and should be avoided.

Some type of connectors are best avoided on motorcycles.  Strip connectors which use screws to secure cables and quick splice joints which use a slotted cutting blade to cut into the cable’s insulation layer to make electrical contact both have disadvantages for motorcycles – and they look a bit amateur too.

General Purpose Auto-Electrical Crimping Connectors & Terminals

The best type of connectors and terminals for general use on motorcycles, for overall reliability, versatility and economy, except when multipin connectors are needed, are insulated crimped connectors.  They are widely available and are easily recognised by the standard red, blue and yellow colours used to indicate the cable sizes they are designed to take.

The plastic sleeving around some crimp joints are transluscent and this indicates that the sleeves are heat shrikable after crimping which adds additional support and weatherproofing to the joint.  Heat shrinkable crimp connectors are significantly more expensive.

As well as cable-to-cable joints (“butt” joints and also “bullet” connectors) they are available as a wide range of terminals.  There are rings and fork terminals for connections to screw terminals (such as a GoldWing’s Accessory Terminals or battery) and there are “female push on” connectors to fit the standard sized blade connectors on relays and other components.

The colour of the plastic insulation sleeve, red, blue and yellow, indicate the increasing size of cable they are intended for.  The smaller, red, size is suitable for most motorcycle applications but blue and even yellow connectors may be needed occasionally to take larger cables or to crimp more than one cable into the same connector, which is a useful way to make a branching connection.

They are relatively inexpensive, although you will pay more for small packets from Car Accessory stores than you will if you buy from trade sources such as CPC.  Boxes which contain a selection of sizes and types are available and that’s a cost effective way of acquiring a small number of most types of terminal you might need.  It will however pay to buy the connectors you will use most often, for example the small size (red) butt connectors in trade packs of 100 which can cost less than £2.

Ratchet Crimping Tool - essential for reliable joints

Ratchet Crimping Pliers

The key to making reliable crimped joints is to use the right tool to do the crimping.  You need to apply just the right amount of deforming pressure, enough to grip the cable firmly but not enough to damage it.  This can only be done if you use the correct size connector for the cable and also use the correct type of ratchet-type crimping pliers.  These pliers automatically release once enough pressure has been applied, so you know when you have got it right.

They wont release until you have applied enough pressure either, so as long as you have chosen the right size connector for the cable and put it in the correct place in the correct pair of jaws (of which there are three, one for each colour/size) it’s quite difficult to get it wrong.

Ratchet crimping pliers will make two parallel crimps which look neat and provide a reliable and durable joint.

A cheaper but much less satisfactory alternative is a pair of manual crimping pliers.  These also have three colour coded jaws which helps to make a reasonably effective crimp but you have to judge the correct pressure yourself and this is much more demanding of strength as well as precise control of the force you apply.

Except for emergency repairs if I had no alternative, I would not use manual crimping pliers.  A ratchet crimping tool is well worth buying if you are going to do any wiring work on your own bike; they cost more than the cheaper pliers-type but they are well worth paying for.  They cost up to £15 but you can sometimes get them significantly cheaper, perhaps as little as £10.  If you can’t afford a pair borrow some rather than bodge the job.

The cheaper pliers-type crimping tool is often sold as part of a kit containing a selection of crimp joints and terminals keep them with bike’s tool kit for emergency repairs but don’t use them unless you have to.

various types of multipin connector

Multipin Connectors

Multipin connectors are useful when you need to make a service joint in a group of two or more cables. Crimp pins and sockets are used to terminate the cables although soldered types are also available.  The cable terminals fit into specially shaped plastic plug and socket housings which can then be pressed together (and usually then click into place to be held together) to form a reliable electrical joint.  As long as the cables go into the correct place in the plastic housing when the joint is first assembled they will allow the joint to be disconnected and re-connected as necessary while mixing up the circuits.

A wide variety of types and sizes of multipin connectors are available including weatherproof and miniature ones. There are industry standards for pin spacings but the different connectors are not usually interchangeable, which is one of their advantages.  On your GoldWing you will find lots of different colours and shapes of multipin connectors, chosen to be different so they cannot be wrongly connected.

For making service joints in accessory wiring looms, which deal in the main with power distribution, so mostly pairs of cables, it should be possible to choose a single type of multipin connector which will serve all your needs, simply by using two, three, four or six way connector housings as necessary.  They will all take the same type of crimp pins and sockets so you will only need to buy one type and one pair of crimping pliers.

Multipin connectors use non-insulated crimping pins and sockets, so you will need a different type of pliers from those described above for use with red/blue/yellow insulated fittings.  If you are only making up a small number of joints you may be able to solder or hand crimp the connections using ordinary pointed nose pliers to save this cost, but you will need to take care to achieve robust and reliable connections.

Multipin connectors are nearly always asymmetrical, so they will only mate in one way, to prevent the cables being connected up the wrong way. The type in the photograph uses chamfered edges to achieve this.

For service joints is looms which have only one pair of cables “bullet” crimp connectors provide an alternative which saves the cost and complication of  kitting yourself with multipin outfits.  Since bullet connectors have male and female versions you can force correct reconnection by using a conventional arrangement.  I use female bullets for live (i.e. upstream, positive) cable ends and males for the negative return.  The other side of the joint (which is dead when disconnected) is done the other way around.  This arrangement avoids any risk of a “live” uninsulated terminal end coming into contact with the bike’s frame.

Hitachi 3 way socket (left) and plug housings

Hitachi Connectors

Hitachi connectors, also known as 2.8mm mini latching connectors, 2.8 mm being the width of the pins, are a particular type of crimped multipin connector useful to Wingers because they are used by the manufacturer for some piurposes on GoldWings, for example the 3 way type matches the GL1800s Accessory  Connector which Honda provides under the left glovebox.

(This socket is powered from the same fuse which protects the bike’s Accessory Terminals in the main fuse box, so it’s only live when the ignition is on or switched to “Acc” and the total current drawn from both socket and terminals cannot exceed 5 amps.)

Honda don’t supply a plug connector to fit this socket with the bike but they are available commercially.  A special crimping tool is need for these non-insulated crimping pins but you can probably manage to crimp with a pair of pointed nose pliers if you’re only doing the odd one.

Hitachi connectors are available in two, three four and six way variants in UK from Kojaycat.   The Honda GL1800 Accessory Socket under the glovebox takes a three pin plug housing – although only the outer two pins are used.

Matching Cable sizes with Connectors

The cable sizes needed for motorcycle accessory wiring vary from relatively heavy cable for battery leads to groups of relays to hair-thin cables which are often supplied with LED lighting.  Information about choosing which size (i.e.thickness) of cable you need to carry the electrical load in your accessory circuits will be provided is another article in this Series, when fuses are also covered, so for now we’re assuming you ae using the correct size of cable and so you need to match it with the connector.

It is possible to get all technical about measuring cable sizes because each type of connector will be specified somewhere as being suitable for cables from this size to that.  But in practice, certainly as far as standard auto-electrical crimp connectors are concerned, if the bared cable will go into the hole and won’t pull out once it’s been crimped using ratchet crimping pliers, it’s a reliable connection.  It’s a bit more challenging that that with non-insulated crimping joints but the same principles apply; if the tangs are properly wrapped around the cable and the insulator after crimping and the cable won’t pull out you’ve made a good connection.

So it ain’t complicated; you bare the cable (or combination of cables, then twist them together and trim to the right length) and select the correct connector to fit over them. If they are a sloppy fit going in the crimp joint is likely to pull apart easily, so you will need to use a smaller connector or thicken the cabl;e by baring it further and folding it back along its length.  If necessary, for example with the very thin cables which are supplied with LED accessory lights, you canb thicken the end of the cable by tinning with solder.

Sometimes you may need to connect a thick cable (or several cables as a bundle) to a thinner one.  If you are making a butt joint you may be able to balance things up either side of the connector but failing that choose the smallest connector which will take the thickest cable or bundle, then thicken up the thinner side by folding the end over or if necessary using solder.

With non-insulated crimp connectors you can sometimes accommodate a thin cable by trimming the length of the tangs with side cutters.

Further information about selecting cables will be provided in a later Article but to view the wide range of sizes and colours of automotive cable which are available, in cut lengths as well as complete reels, visit the Kojaycat Website.

Next Article

Part 4 in this series will deal with Circuits, Cable Sizes, Fuses and Relays.

A list of UK suppliers of components, cable and connectors will be provided with the final Article so please recommend your favourites in case I’ve not come across them.