Replacing individual wires within the loom ...questions.

[utopia]

I have a wiring issue on my 750.
Often, when I press the button, the starter wont spin until I waggle the bars ever so slightly from side to side.
This began a few years back, at which time I traced and fixed a broken wire from the start switch to the solenoid, where it passes the headstock. This is apparently a common fault.
In my case, although the copper conductor was broken, the insulation remained intact, though there was an area where the pvc looked a little pale, as if it had been stressed by a tight bend or somesuch.
The fault reappeared the following year, but this time cleaning the two pin plug to the solenoid seemed to cure it.
Then it reappeared this year.
I strongly suspect that the same wire has broken again, possibly due to having been overstessed somehow during manufacture of the loom (hence the pale discolouration of the pvc insulation which I observed).
Obviously I'll confirm my suspicions by running a bypass wire to duplicate the original, but......

The wiring diagram, though only a schematic and not necessarily describing every last physical detail of the loom, shows this wire as a single conductor, direct from the switch to the solenoid, with no internal connections to any other wires.
So I was wondering how easy it might be to draw another new wire into the loom, using the old one as a puller.
I'm reluctant to start cutting off the sheathing as its in a point of high stress around the headstock.
I fancy that it would be worth making the new wire as slippery as possible, maybe with a good dose of wax polish or silicone grease. Also the connection would need to be smooth and snag-free.

Before I have a go, I was wondering if any of you had attempted such a job and had any advice to offer.

[Capo]

http://isswww.co.uk/Wire-Pulling-Lubricant/Ideal/Ideal-31378-Aqua-Gel-1qtr-Squeeze-Bottle/?source=googleps&gclid=CKXjtPyhv7sCFSbHtAodiVQAUQ

[tricky73]

I would just run it neatly on the outside cutting it in at each end, then either use insulating tape and or the felt covered tape to the original loom

[utopia]

Hmmmm. Water based gel ?
Now there's an idea ! :eek:

[Dukedesmo]

I have run extra wires through looms before and usually not too many problems.

I've had the loom off my bike (yours should be the same?) and I reckon it would go through easily enough as there is plenty of 'slack' but I would do it with the loom off to get a straight run as you'll struggle round any bends, if it's not too long a run you may be able to push some thin rod (I like stainless welding wire) through as a guide?

Otherwise solder the new to the old to avoid breakages, maybe use some heatshrink to cover the join, a bit of lube and it should through go easily enough.

[mutley]

it might be tough to pull new wire through id run it on outside then use loom tape I've done repairs on cars can't tell when its done just take your time with it so you get a nice finish good luck

[gary tompkins]

I would remove the sheath completely on the damaged section. It would make the repair easier to do properly, and allow you to spot other problems. You could just re-tape it afterwards. I had to do this to cure the same issue on my 900ie when it was about 3 years old, when I found it had 2 broken wires and another just about to snap. Never had any more problems with loom after that.

[utopia]

Thanks everyone.
Some useful advice and encouragement there.

I need to replace an 80cm length of wire, of which about half needs to be inside the main sheathing which runs down the right hand side, from headstock to rear of engine.
Its a fairly straight run and, having loosened various cable ties and removed the plugs from the ends of the wire, I can now gently pull one end and see the other end moving.
I think it bodes well for being able to run in the new wire, but I'll have to wait 'til after Christmas now, to get some of the correct colour.
I am half tempted to heed Gary's advice and cut the sheathing right off though, so as to be able to check the other wires in that area.
But I've got a few days to ponder that.

It was, as I had thought, a break in the wire just next to my previous soldered repair, probably caused by the extra stiffness of the soldered section which focussed any flexing onto the immediately adjacent area of the wire.

I was wondering whether talcum powder might be a suitable lubricant to help threading in the new section.

[Dirty]

First water based lube, then talcum powder! What's next a light spray of Chanel No5 and a candle light dinner? :)

[buzzbomb]

What's next a light spray of Chanel No5 and a candle light dinner? :)

Now that sounds good...:idea:

Hope we're all invited...:thumbsup:

[pooh]

Utopia
What colour wire do you need? I built a custom loom for my bike and have some cables left and connectors. I am working in leicester Monday to Friday so could bring some down.

Pooh

[utopia]

Utopia
What colour wire do you need? I built a custom loom for my bike and have some cables left and connectors. I am working in leicester Monday to Friday so could bring some down.
Pooh

Thanks for the offer.
My reply is late because I could feel the onset of a flu bug (now well established) and didn't want to suggest a visit to catch that.
But you'd be welcome to call in for a cuppa anytime, once I'm no longer infectious.
I'm usually about.

Thanks also to Flip who has, I believe, put some bits of wire in the post (though the local rogue postie may have even nicked those because they seem late in arriving).

However ......

My choice of wire seemed to be between matching the original 0.5sq mm stuff, in blue without the correct red tracer, or upgrading to 1mm sq wire which is available in the blue/red sheathing.
I was tempted by the upgrade, but worried that the extra thickness would make it difficult to pull through the loom.
Then, just as I was dropping off to sleep the other night, the penny dropped.......
Blue is one of the std colours in modern domestic wiring. There was every chance that I had a bit hanging around.
The following day my odds 'n sods bag yielded a promising length of 2-core cable bearing a plug with a nice, low 5amp fuse (so the wires were thin).
Counting and measuring the strands revealed that the original wire was 16 strands at about 0.2mm dia, giving 0.5sq mm total csa. The household stuff was 41 strands at about 0.15mm dia, for a total of 0.7sq mm.
This was actually perfect, as it fell between the std wire and the next biggest available size from auto electric suppliers, and gave me a better chance of slipping it through the loom.
Also, having a higher number of smaller strands, I reckoned it would be less likely to break. It certainly felt much more supple.
And it seemed to have the required thinwall pvc insulation too.
Its shade of blue was even a perfect match for the original.
So I decided to crack on and use it.

Cutting the tale short, the new wire was installed in double quick time and my three year old electrical glitch should now be permanently cured. :)

[utopia]

As part of the above, I learned a new soldering technique which is worth a separate post.

In the past, when joining two wires, I've first cleaned, fluxed and tinned both ends, then laid them next to each other and reapplied the soldering iron to fuse the two together.
This usually leaves a large amount of solder and a fat joint, which is very stiff and often causes the wire to break again soon afterwards in the soft area nearest to the join (as had happened on this occasion after an earlier repair).
This time I bared about 1cm of each wire, cleaned them and applied rosin flux.
Then I pushed the two ends together so the individual strands interlocked.
I had tried this before, but the result was a junction that splayed wildly, like a ragged bow tie, and was far too big a joint, and hence the idea was abandoned.
This time I came up with a cunning plan.
I cut a 50cm length of cable and stripped all the insulation, leaving me with 16 very thin strands.
I took one of these and wound it two turns around the central "waist" of the ragged bow tie, pulled it tight and then slid it outwards. This pulled the strands together perfectly.
I repeated the process for the other ragged end, and I now had a super neat, perfectly cylindrical, interwoven joint, which was no larger than the insulation.
I did not clean these wrapping strands, in the hope that they would not take solder readily, and could therefore be removed easily afterwards.
A quick dab with the soldering iron and I had the perfect, smooth joint which required minimal cleaning up before shrinkwrapping to result in a smooth, sinuous continuum of cable.
In electrical terms, I imagine its just about as good as it gets, and it was certainly strong enough to pull the new wire into the loom without coming adrift (despite a couple of tight spots). It also didn't hold so much solder, so there was perhaps less stiffening and the cables were coaxial rather than parallel, both of which seemed more likely to avoid subsequent breakages close to the joint.

Its sometimes the little things which make all the difference.
I had recently been somewhat reluctantly drawn to the conclusion that butt crimps were a better way of splicing two wires, but there was always something about those that left me less than totally confident in them.
Furthermore, for a neat job you really needed a decent crimping tool, and the crimps themselves were generally unavailable in anything less than two sizes too big anyway.
But with my new, ragged bow tie (reformed) method, soldering has now regained its rightful place as my preferred method in most cases.

So next on the list is to replace the individual butt crimps on my hard-wired, alternator-to-reg/rec leads with soldered joints, which will hopefully give a reliably lower resistance joint.

Incidentally, I reckon the ideal covering for individual cables joined in this way, for those of you who might not yet have come across it, is the heatshrink which comes lined with hotmelt glue.
Sooo perfect for the job, I almost wonder whether you actually need the solder at all. And it shrinks three to one as well, so it passes over terminals etc if needed.

Sorry once again for lack of pics.
Tis true that a picture can be worth a thousand words.
But sometimes the reverse can also be true, like when the film is never quite as good as the book was.
I myself have developed an odd liking for listening to the football on the radio.
I prefer the evening matches as I can paint some magical pictures of the floodlit stadium (that's the old stadium, with standing on the terraces and close-up action, not the new hyperdrome where they're actually playing).
And I don't really like football.

[pooh]

Utopia
Drop me a pm with a phone number or address coffee sounds good.