Loom and part i have labelled but ink faded

[Lobo]

Mike... bad news, me again..

You wrote "so to replace that section please go into detail "

This repair to your (green / earth) wire within the loom. Basically you'll need:

(1) A replacement length of wire, MINIMUM 15A rating. Try shopping here, look in the menu 'Cable', and within here either Standard... OR Thin Walled Cable. The latter is more modern, with an abrasion resistant sleeving, but a little less pliable than the Standard cable.  Read the intro blurb for each, and make your mind up. (think I'd go standard). Then choose a wire that is greater than  15A capability. Then choose Green (!) and the length you want.

http://www.autoelectricsupplies.co.uk/category/10

I think you can also get 15A automotive wire from Halfords... and maybe Maplins.

(2) You'll need to insulate the joints you'll be making, and I'd recommend you use HEAT SHRINK TUBING. Go to the same link above, and within 'Sleeving' menu find 'Heat Shrink Sleeving'. Choose the colour, diameter and length. (This diameter will approx halve when heated, don't forget, it'll initially have to fit over your 'bulky' (ish) soldered joint. Ie don't skimp on the diameter)
(you can also get heat shrink tubing from Maplins)

(3) You'll need a 40W soldering iron + solder..... Maplins / Halfords, < £15 or so

(4) Wire strippers.... Maplins / Halfords, £5 tops.

(5) Black insulation tape to bind the loom back together @ the end of the repair.


What you do...

Cut back the existing loom external / main black insulation up & down the abraided earth wire until you get a couple of inches of 'Virgin' green wire each end. Cut out the bad bit. (do NOT plan a joint where the loom takes a turn etc - ie choose a straight run)

Strip back about 1cm of insulation on each end, and ensure the copper wire is CLEAN.

Cut a length of your new green wire to splice in, and (again) strip about 1cm of insulation off each end.

'Tin' each of the 4 bare wires individually .. ie heat them with the soldering iron & apply solder.

(if you're not comfortable with soldering try a few joints away from the bike & on the bench until you get happy)

Join one end of your new wire to the existing loom, lay the tinned ends side-by-side and heat with the iron. Apply more solder if you have to.

Cut 2 pieces of your heat insulation tubing, about 3cms each, & slide over new repair wire splice. Move it well up the new splice, ie well away from the heat of your next solder joint.

Solder the second joint. (these joints must look shiny silver on completion, not dull)

If there are any 'sharp' points about your joint send the missus to the shops & nick her nail file to 'make it all better'

Slide each piece of heat shrink tubing over each solder joint & heat with a hair dryer until it shrinks tightly over your repairs. (you can use a match / naked dull flame... but get the tank well away!) (Again, if new to heat shrink tubing play with a few test bits until you've got the hang of it.)

Bind the whole repair area / loom back up with the black insulation tape. Take care with the ultimate routing... you were LUCKY you abraided the earth wire, chances of that happening versus the others!

Pour yourself a beer...

Enjoy!

[MikeM]

thanks think I will go for ... do you think that's suitable

28/0.30, 2.0mm2, 17.5A - cable OD 3.3mm

heat shrink

Int. Dia before Heating 4.8mm, Int. Dia after Heating 2.4mm

[Lobo]

Sounds good. If you are ordering from autoelectrics perhaps (for 81p) also buy a meter of the larger size heat shrink as well - this stuff always comes in handy.

[MikeM]

about to start trying to fix this earth wire and bit concerned...... opened up the loom a lot more and more "rubbing" evident

different places still on the green wire have rubbed through... do we still think its just a bad earth ?

added some more pics of the fuse box and again green wire looks like something has happened



on another wire looks like someone has mended the black wire in sections

need some advice before I start replacing the wire and cleaning up the connections

[LesterPiglet]

That last green looks melted to me.

[MikeM]

that's coming out of fusebox hence concerned


bad earth still  ?

[Lobo]

Mike - guess you realise you've a fairly big issue here, and from the pics it'd seem your whole earthing system needs renewing. There appears to be so much damage that its a fair bet there's more you can't see.... certainly a replacement 'green' wire through the whole bike appears needed, if not a loom.

What's caused this? Two possibilities come to mind...

(1) the previous owner installed excessive lighting / electrical loads and replaced the Honda rated fuses with higher amperage ones.

.... or, and more likely...

(2) the bike's multiple earthing points were poor / in disrepair.

Up & down the bike there are individual circuits.... denoted & protected by the fuses. Each circuit has its own current rating... eg 15A, 5A... and so on..... and yet they all share the common Earth wire; which is rated @ 15A.

Now, and for arguments sake, if this green (15A) wire was earthed only at the rear mudguard current from the headlamp, indicators, horn, stop, tail, ignition coils, alternator exciter coils etc etc would all be 'sharing' the wire / connection & very quickly it'd overload & melt. (= yours?) If however all the earthing points were good, the front end of the bike's current will earth into the frame @ coils area, the mid bike current around the battery box area, and the rear end into the rear frame earthing point. IE a 'concentration' of current would never be allowed to build over the length the wire.
Very, very over simplistic, I know, but hopefully an illustration. (think of a busy motorway with all slip roads blocked.. it'll soon overload as traffic can't bleed off of it)

The integrity of your earthing wire is very much in doubt, and a repairing of the visible damage will still leave the invisible bits waiting to fail. Bad news, but whilst you've the bike in bits now is the time to fettle it. Other folk may have different views, but given the loom may be 35 years old with brittle insulation, fatigued wires about the steering head, dirty connectors etc maybe just bite the bullet & order a replacement loom for peace of mind. Failing this, run a new green earth wire to all user points in parallel to the old / burned out wire.

Crappy, I know. See what others have to say, hopefully there may be a better way forward.
Simon

[MikeM]

hi

thanks for info, time to stop and think.

It appears the green wire damage goes to the coil?

fusebox green wire again looks hot shall we say.........

so I have another spare loom but not sure how good that one is will have to open it up.

if I have to use new loom looks like I will have to wire up clocks which I am concerned is beyond me

will await more opinions 

[Trigger]

Mike, mine was the same. I got hold of a new fuse box and replaced all the earth wire. It is weird because mine looked identical to what you are showing in your pictures.

[MikeM]

did you take any pics.... how does/did buying a new fusebox solve the issue ?

want to learn about electrics

[Trigger]

Don't know what caused the problem in the first place. The fuse box was melted and beyond repair. I picked a NOS one from a German Honda dealer for £25.

[Trigger]

The strange thing i found Mike, was in picture 4 the green wire goes from the block connector to a bundle of green wires (take the tape off and your see a soldier blob) but no other green wires are damaged. And i see from your picture, no other green wires are burnt.

[Lobo]

Just one other thought Mike, and am wondering whether all this damage can be a result of a regulator failure.... ie the alternator is producing full power all of the time. This though would quickly trash the battery... did that happen? Trigger, did you replace any other electrical components @ the time you replaced the fuse box / service the electrics (eg cleaning up grounding points)?

Many 550 owners on here (I'm not), is this a common fault gents?

[LesterPiglet]

Mine is all ok. I changed the rectifier a long time ago but I can't remember why now. It's from a 750.

[MikeM]

lobo cant answer that question bike sat since 1983 ?

who knows whats happened since ?


hopefully geting a new fuse box from member going to attempt to replace al lthe green wire through out the loom and clean up al lcontacts and sort out grounding points

if that dont work the bike will appear in parts on ebay