Motoscrubs.com

I am trying to sort out a wiring fault in my headlight shell, the bike is a 250 Narrow case mark 3 with what looks like a Mach 1 system or widecase set up in a 130 shell. I have a Mach 1 diagram but it shows no colours at all (clymer) . I am particularly interested in a brown wire that arrives in the loom but is loose. Any Idea?.

Morning Bob,

I put "wiring color" into the forum search window (top right of screen) and came up with this coloured diagram previously posted. I know it says "Sebring", but, if you look at the top of the diagram it also lists the "Diana, MKI 250's", so it might be of use. If not, there are a further 140 plus returns to the search for you to trawl through! Happy reading!

Hans, may also be along later to offer advice, as it was he that made the posting.

I suspect that it might be for a pilot/parking light, but do not quote me on that.

Motoscrubs_forum_colored_wiring diagram_Diana_MKI_Sebring_thread

Good health, Bill

Hi Bill, I have taped up the offending wire and everything is now working apart from idiot type light bulb on headlight that has never worked anyway.

Morning Bob,

I do hope that has solved the problem, nothing worse than having a loose wire flapping about in the headlamp.

Hope that you'll be able to enjoy riding the wee beastie now.

Good health, Bill

Bevel bob wrote:Hi Bill, I have taped up the offending wire and everything is now working apart from idiot type light bulb on headlight that has never worked anyway.

Think you might find that's the charging idiot light, connected to the reg/rec by the mystery brown wire

Yes charging indicator light , I was thinking the same, Any idea how it works? The alternator has been un-grounded and coils linked with a modern rec/control box. I think the charging system is now seperated from the rest of the bike so the light would not work anyway with the newer layout?.

Bevel bob wrote:Yes charging indicator light, I was thinking the same, Any idea how it works?

As I understand it, the original system works like this:

1. When you turn the ignition key, but with the engine not yet running, the light comes on. What that tells you is that the battery is charged - useful info, for a 'battery-plus-points' ignition system.

This is done by a circuit that goes from the battery, via one of the connector blocks, thru the ignition switch, thru the idiot light, then to the reg/rec and so to ground (via a 28 Ohm resistor inside the reg/rec).

2. When the engine is fired up, the light goes out. The purpose of this is to tell you that the charging system of alternator plus reg/rec is working.

This is achieved by some internal circuitry in the reg/rec (I'm lead to believe it's done by a balancing charge of 6 volts being supplied to the charge light terminal of the reg/rec, but don't quote me on this).

Bevel bob wrote:The alternator has been un-grounded and coils linked with a modern rec/control box. I think the charging system is now seperated from the rest of the bike so the light would not work anyway with the newer layout?.

Not quite sure what you mean here ... but at the end of the day, the question is: does the new reg/rec support a charge light function? Some do, some don't.

Hi, I'm new to the forum and this is my first post. I am currently completely rewiring a 200GT. It has the same wiring as the Monza and Mach 1. There is a wiring diagram floating around that you can use. It's in many of the books and this website. It's similar to the Sebring but not the same. The light and ignition switches are different. The Monza wiring diagram is accurate except for the horn switch.

On the diagram, if you look at the headlight there is a pink wire running to it from the light switch. There also looks like there is a high/low beam switch at the headlight. That's not correct. The pink wire is a hot wire and it goes from the light switch to the horn switch not the headlight. The horn switch is also the high/low beam switch. From the horn switch there is a yellow and green wire that runs to the headlight. One is for the high beam and one is for the low beam. They are both hot.

So If you have the standard 6 plug narrow case rectifier, the colors are as follows. Red and gray are hot(pos+), The two yellows are from the generator, the green is a ground, and the brown is a sometimes ground that works until the RPMs reach 1000. This allows for the charging light to be on when the ignition switch is on but turn off when the bike is running and the generator is working properly.

Lastly the (my) ignition switch has four poles. When the key is in, the opposite poles are connected. In the diagram the red wire connects to the white wire that runs to the coil and the brown wire that turns the charging light off and on. The gray wire connects to the black wire that goes the the fuses that go the lights and horn. Hope this helps.