1986 K2 light switch, headlight, wiring issues

[themoudie]

Out last night, the dipped beam shone like a glow worm and the main beam warning light glowed like a glow worm at the same time! Switched to main beam, which shone brightly and the main beam warning light shone brightly. I usually ride during the day using the yellow/orange LED bulb in the parking light holder. This was working OK.

Once home, I was able to replicate the dimmed dipped beam, dimmed main beam indicator light shining and the parking light also came on! Main beam remained main beam only and bright as did the warning light. It would appear that there is a partial short in the handlebar switch between the headlight feeds? But, I also thought that I should check inside the headlamp shell and the headlight bulb, "Just in case"!

I have never been into the headlamp shell since purchasing the bike last year. Quite how the indicators work, when the white/black feed for the right-hand indicator and the green/black feed for the left-hand indicator or connected through the rat's nest, I am not sure? There are single black wires coming from the indicators and the whole lot are then tap connected into the blue wire coming from the common ground that also is tap connected into the headlamp bulb holder to the wire running to the right-hand side connector of the headlamp, when viewed from the rear of the holder.

How does the Yellow/Green wire wired into the back of the parking light work? I thought it should connect the 'RED' lights warning light and then the 'HIGH BEAM' warning light, then to ground!

I have a 'blue book' and think that the wiring diagram on page 115, 'LEGENDA Mod. 350' is the one I should be using. Is this correct?

There is also a thread on the Moto Morini 500 board, with a single post in it that is very useful. Link:http://www.morini-riders-club.com/forum ... ?f=7&t=277

Maybe the left-hand handlebar switch isn't the problem. I wish! I intend to rewire using Japanese type soldered and crimped connectors, with covers, heat shrink and self bonding tape where necessary and the wiring diagram's, wire colours. Positive comments and advice would be appreciated.

Thank you and good health, BillR

[3potjohn]

There are colour wiring diagrams on the members pages W which should help a lot.
What I would do is put an order in to Vehicle Wiring Products for the following which will stand you in good stead.The website is good.
Thin wall cables, all the correct colours available price per metre.Thinner and lighter than the original.
PVC sleeving, heat sharing sleeving, roll or self amalgamating tape.
Non insulated terminals:
blade terminals male and female and corresponding insulation.
Japanese connectors male and female and corresponding insulators, these interlock into each other and seal very well. I dab a blob of silicone sealant into the back if exposure to water an issue.
The best crimp tool you can get. I have their MP71 for non insulated terminals. Just take care to insert the terminal properly.This has been a Godsend.
I do not solder.
Photographing the process and note taking is invaluable.
I may photograph my rats nest and pm you.
Good luck,John

[themoudie]

Aye John,

Thank you for the info and advice. The advice about the wiring diagram is very helpful.

I already have an account with VWP and have all of the items that you suggest. I agree with your use of the thin walled cable. Plus, I have found this tool to suit my needs very well: CK_495001_wire_strippers They are widely available and reasonably priced.

When rebuilding my Ducati 450 MKIII, I made a new wiring loom, including relays etc to remove the current from the switches etc. A good digital multi-meter is also useful.

Off to wrestle with coloured spaghetti!

Good health, BillR

[mbmm350s]

Hi Bill,

When rebuilding my Ducati 450 MKIII, I made a new wiring loom, including relays etc to remove the current from the switches etc

A very good idea to add relays.

Also I prefer to use the frame to do mechanical things and use wires to do electrical things like proper earth wires!

Originally on my 78 Sport the earth for the speedo light was via the speedo cable!
Mark

[themoudie]

Aye Mark,

Also I prefer to use the frame to do mechanical things and use wires to do electrical things like proper earth wires!

I couldn't agree more, even though it can make the number of wires greater, with the 'thinwall' cable, this isn't usually a problem.

Rather than heat shrink, especially with added glue (!) or self adhering tape, I have used this twist wrap braided sleeving to hold the loom wires together, it makes a tidy job and it is easy to add or remove cables and trace them. VWP_twist_wrap_sleeving

Good health, BillR

[Daddy Dom]

Thin wall cables, all the correct colours available price per metre.Thinner and lighter than the original.

How many amps wire please? There's a huge selection.
DD

[3potjohn]

I am away at present but think I have generally used the 1mm cable which might be overkill for most applications.You can go up a grade or two for charging/ battery . It is quite resistant to rubbing through as well.
I have not had to do any of the charging side yet though.
John

[Ming]

I've used the finest (I think), which at 11A capacity is more than enough for most applications.

[themoudie]

Aye DD,

As Ming has said

11A capacity is more than enough for most applications.

I quote from the VWP cable page

The following equation may prove useful to work out a cable size required : Watts divided by Volts = Amps

So, if you are using a 60W headlight bulb, in a 12v circuit that = 5 Amps (0.5mm cable) and for a 6v system you might choose to use the 16.5 Amps (1.0mm cable).

However, as you will have noted on the VWP website catalogue, the greatest range of cable identification colour combinations is found in the 16.5 Amps (1.0mm cable) range.

Good health, Bill