wiring

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dunk 1
Posts: 208
Joined: 25 Oct 2007 18:16
Location: cumbria

wiring

Post by dunk 1 »

Hello - going to use the time available to re do some of my wiring - please bear with me as I am not familiar with some of this (I have tidied some of the existing wiring replacing connectors etc) but completely re-doing bits seems quite daunting.
First is wire size - what seems to have come off is 3 mm single core standard wire, which according to VWP s site would make it 27.5 amp. Is it best to replace it with the same or thin wall? I ask because the multipin connectors sold by VWP are designed for cable less than 2.5mm. can anyone suggest an alternative.

I will also need to do some soldering which I will practice a lot first, there seems to be an awful lot of soldering equipment out there, what size/ wattage of iron would best suit the job - also what style of tip - thanks

The wiring from the controls is obviously the most difficult bit - the sleeving is damaged but all wires and joints seem functional. rather than risk destruction by solder would it be wiser just to replace the terminals and sleeving leaving the rest well alone?
thanks - Duncan
dunk
MickeyMoto
Posts: 2415
Joined: 22 Nov 2008 17:41
Location: Even further oop North

Re: wiring

Post by MickeyMoto »

Hi Dunk,

Buy a decent crimping tool... being ex-Telecom I used to solder as I was trained to do it properly, but have now reverted to crimp only. I used to crimp and solder. Probably find modern solder is not up to much, either!

Looms for 350s are (were) available from Italy. About €60 plus a million lira for postage. I think some people have used them and are impressed. I think there are two versions.

Interestingly, the diagrams supplied have Morini-Riders-Club on them... :)

Mike.
dunk 1
Posts: 208
Joined: 25 Oct 2007 18:16
Location: cumbria

Re: wiring

Post by dunk 1 »

Yes have see the looms ( and was thinking of purchasing) but wasn't sure about getting them from Italy under current conditions -and of getting the right one for a 79 with starter motor also - also presumably will still have to solder to the switchgear. speaking of which - throttle side is fine but my left hand switch plastics seem very fragile and I am not sure the dismantling and reassembling is going to help them much, is there a replacement available?
thanks - Duncan
dunk
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buzby
Posts: 190
Joined: 14 Apr 2006 18:31
Location: southampton

Re: wiring

Post by buzby »

Another ex Telecom engineer here. I crimp and solder the connections as I was trained to do. Too much heat from the soldering iron is bad so a small soldering iron and fine solder with added flux is fine.
Dave.
David
75 350 Strada, 76 350 Strada, 76 350 Sport. 80 250 vee, 72 Triumph TR5T and 81 Honda CB250RS
MickeyMoto
Posts: 2415
Joined: 22 Nov 2008 17:41
Location: Even further oop North

Re: wiring

Post by MickeyMoto »

The big mistake is to place the iron on the joint and then solder. Place the iron one side and the solder on the other and it will flow to the iron via the joint...
Al B
Posts: 47
Joined: 03 Feb 2017 20:34
Location: Luton, UK

Re: wiring

Post by Al B »

The automotive world has stopped soldering and used only crimping for decades because solder wicks between the strands along the wire and causes a stress raiser a short distance away from the terminal. When subjected to vibration the wire flexes at that point, the copper work hardens and strands break giving high resistance joints, overheating and failures. A properly crimped terminal supports both the wire and the insulation.

Soldering is fine for non-moving parts or where wires are wrapped/tied/bound and fixed so that they don't move in relation to the terminal they're connected to.

Al
dunk 1
Posts: 208
Joined: 25 Oct 2007 18:16
Location: cumbria

Re: wiring

Post by dunk 1 »

Hello - thanks for the input on whether to crimp and/or solder - and as I say I will still need to solder to the switch gear. Wonder if anyone can still enlighten me on what size/amp of wire to use for the general wiring and whether replacement main switch gear is available anywhere - thanks - Duncan
dunk
MickeyMoto
Posts: 2415
Joined: 22 Nov 2008 17:41
Location: Even further oop North

Re: wiring

Post by MickeyMoto »

Hi Duncan,

You will have to search for the switchgear. I have seen a few come up on ebay and the like, but the prices are not low.

I am looking for one at the minute, but may replace the non original one with a later Excalibur one. I spent an afternoon translating the wiring colours so I could join it to the loom, but the wiring has also been mangled. I think I'll buy a new loom and do the complete job. If I find one I'll let you know.

Mike.
dunk 1
Posts: 208
Joined: 25 Oct 2007 18:16
Location: cumbria

Re: wiring

Post by dunk 1 »

Thanks - have noticed mdina do one that is listed for a Ducati tat looks the same but a bit pricy
https://www.mdinaitalia.co.uk/079738458.1.html
and you would have to sort the wiring
Might give it a go with mine and if I mess I up or it self destructs then look at one of those
dunk
mbmm350s
Posts: 666
Joined: 22 Jun 2018 10:18
Location: Reading UK
Location: Berkshire UK

Re: wiring

Post by mbmm350s »

Hi Dunk
Wiring is not hard, just practice before the soldering of the switches which can get damaged by heat.

Some tips from an another electrical engineer.

Do buy a decent ratchet crimp tool, the kind that will only release when the crimp has been done correctly.
The proper automotive crimp tool will suit 3 different sizes of crimps
Buy the tool from the same supplier as the crimps to ensure compatibility
Double check the cable size as crimps will be available in different sizes.
Check the crimps are suitable for thin wall if that's your choice
Buy plenty of crimps they are really cheap.
I don't bother with soldering in vehicle applications. It takes double the time and damages the insulation if you aren't good at it.
It also hardens by tinning the separate strands of copper and making them appear as solid core,
this affects the reliability of the joint. AlB already mentioned this.
Do buy a good quality wire stripper that can be correctly adjusted
Do run extra earths back from headstock area, rear tailight area to fusebox area.
Do stick to the colours in the wiring diagram if you aren't used to wiring
Don't forget to sleeve and put the insulators on the wires before crimping
Do make sure to allow enough slack particularly at the headlight and bars to allow for movement.
you may find talc useful when feeding cables through sleeving.

Switchgear, when soldering make sure you clean it up well first especially where there is corrosion as they aren't easy to solder then.

You should be able to calculate the required loads and hence the current requirements. However do not concern yourself too much as automotive cable supplies are typically quite limited. On the bike you don't need to worry because the distances are small, the loads are small and there aren't great bundles of cables together.
1mm 14/0.3 will be suitable for all accessories, ignition circuits, connections to handlebar switches. unbundled rating 8.75A
2mm 28/0.3 will be suitable for any heavy loads like headlights, generator connections, long return earths unbundled rating 17.5A
using automotive supply cable will give you a good range of colours including trace colours.
for e-starts + battery connections applications you will need a heavier cable.
If rewiring generators I use high temp cable, often the old insulation is rock hard.

Thin wall is useful for car applications where large cable bundles are needed with large loads,
however i prefer the thicker insulation for old motorcycles.

PLEASE PLEASE do not use trailer hookup cable . :evil:


All the best
Mark
dunk 1
Posts: 208
Joined: 25 Oct 2007 18:16
Location: cumbria

Re: wiring

Post by dunk 1 »

Thank you Mark that should cover it - Duncan
dunk
Richard
Posts: 48
Joined: 08 Jan 2018 17:04
Location: Doncaster, UK
Location: North Lincolnshire

Re: wiring

Post by Richard »

I think that the modern thin-wall cable is less flexible than the old standard cable. I prefer the older style cable, especially for steering-head to main frame where there is constant flexing when riding.
Sicxtyone
Posts: 121
Joined: 29 Sep 2018 07:34
Location: Worthing
Location: Worthing West Sussex

Re: wiring

Post by Sicxtyone »

Hi all electrical wizards,
Any tips on cleaning/ rejuvenating the wiring loom, 500 sport. It all looks reasonable just really dirty, was all working as intended when taken off.
Graham.
dunk 1
Posts: 208
Joined: 25 Oct 2007 18:16
Location: cumbria

Re: wiring

Post by dunk 1 »

Mdina seem to have added left hand switch gear in kit form for about £20 less than one wired up if anyone was interested in my previous post- Duncan
dunk
dunk 1
Posts: 208
Joined: 25 Oct 2007 18:16
Location: cumbria

Re: wiring

Post by dunk 1 »

I have be quite happy rewiring the bike so far - decided to do it all myself rather than buy a kit - none of them seemed to fit what I wanted exactly. Now up to the interesting parts - i.e. the switches - first of all they need a good clean all round internally as filthy inside -what should I be using to do this and also presume they need re-lubing on the moving parts - what should I be using to do this?
Also can someone answer a question - mostly the wiring seems logical but why does the black and white wire entering the big block connector to the lights, switches etc turn into two blue wires ( which I associate with earths) and then turn back into black and white wires again later at the next connector? - this does match the wiring diagram.
thanks Duncan
dunk
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