Cable query 2

[Phil C]

Afternnon all,
Even to an electrics dunderhead like me, it's interesting. Some of you might know, from my recent "Cable query" post, that I've been looking at the wiring around my battery compartment (1965 B40F.) Well, today I thought I would replace some of the wiring to my alternator. First up was the GY wire (it stops a few inches short of the casing near the alternator and the gap is made up by a short length of other-coloured wire for some reason, so I thought I'd put a simple length of GY there, and do away with the short bit.) I followed the GY wire away from the alternator, peeling off old insulating tape as I went. Up through the battery compartment it went, did a U-turn and headed rearwards. Exciting, isn't it?! But try to contain yourselves. According to my wiring diagram it should go to the ignition switch. Now my ignition switch isn't at the front of the battery compartment - there is a hole in the tinwork there, so I think it might once have been, but it's now to the right of the seat (and in an awkward place when you're trying to turn the engine off.) Looking at my switch, there was no GY wire going into it. But under swathes of insulating tape, backward of the coil, I uncovered what I think is another ignition switch which?  (Please see photos.) The GY goes there, as does a B, and a BW (I don't yet know where they come from There's also a short stub of W wire coming from it. Going into the in-use switch is a W (which you'll see on the photo becomes U before it enters the switch) and a NW (which becomes a N.) I'm guessing the W is what went into the old switch, now going to the new one.
So again I find myself thinking: what is going on? According to my diagram there should be four wires going into the ignition switch. At my "new" switch there are only two, but there are three going into the old redundant switch. Obviously I'm going to have to find out where they all come from and go to. In the meantime (if you're still reading), any thoughts?  Phil

[Phil C]

Done a bit more looking.Here's what I know so far:
As well as my in-use ignition switch, situated (in an awkward place) to the right of the seat, I also appear to have part of another one, that is not in-use (see photo.)
The wires at the switches are:
At the old switch:
     GY - from the alternator
     BW - from the coil
     W - cut to a short stub , but maybe was once from the coil?
     B - goes along under the petrol tank, I guess to the ammeter or light switch
At the new switch:
     W - from the coil
     NW -  goes long under petrol tank, I guess to ammeter or light switch
This is not very much like my wiring diagram.  Any thoughts and advice please?    Phil.

[Phil C]

Still head-scratching here. Looking at my wiring diagram, there should be five wires at the ignition switch: NW, W, BW, GY and B.

I have all those colours, but they are connected to two switches rather than one. And one of those switches is not in use as such, and was covered in insulating tape.

Phil.

[Phil C]

I guess what I'd like to get out of this is to have just one ignition switch, as per the wiring diagram. Any advice would be very much appreciated.

By the way, here is a photo showing the switch which is in use at the moment. It is positioned immediately behind the rectifier. Looking at Rupert Ratio vol.2, I'm not sure it's a BSA switch.

And I wonder why it's positioned there?

Phil.

[Blackthou]

Hi Phil,

Interesting dilemma. I reckon, whether it's a security enhancement or not, that the new switch is just a coil switched live and the old buried switch does and the other functions that it did when it was solely in use. In fact it probably is in use still. Not an easy one to sort. Do you think the original switch could be reinsated or would you rather it wasn't?

Did you get the notes on my wiring findings  I PM'd you?

[JulianS]

The extra switch is very likely a later Lucas type and may have several switch positions. There may be a part number marked on it.

[Phil C]

Why would someone have two, rather than just one switch? And why would they move its position?
Phil

PS Blackthou, yes, I got your PM - did you not get my reply?

[Blackthou]

My opinion is that the owner wanted an additional level of security, as the original switch isn't secure, then added the second switch. He ran the coil wire to the new switch and then hid the orignal switch also leaving all its other functions operative.

I checked my messages and I can't see your reply.

[Phil C]

Morning everyone, Blackthou suggests a previous owner ran the coil wire to the new switch and then hid the original switch, leaving all its other functions operative. I have a couple of embarrassingly basic questions:. 1. What are the other functions? (GY, B, BW).     2. My wiring diagram shows two wires between the ignition switch and the coil (W and BW.) In my innocence I thought the wiring for a coil was one input, one output to the contact breakers ( where there would be an earth), and of course the HT lead going away to the plug. So I'm wondering: why are there two wires between the ignition switch and the coil?  Thanks for your patience.  Phil

PS Blackthou, my sent box confirms I PMd you on 1 May. Just to say thanks basically. In your junk mail perhaps?

[JulianS]

The ignition and lighting switches are interconnected to provide alternator coil switching for charging on the original 6 volt system and to provide the emergency start facility.

Not explaining your extra switch but with the original ignition switch in circuit the BW to the coil from connection 15 on the switch is part of the emergency start circuit, only connected when the ignition switch in the emg emergency start position. If you follow the wiring diagram I posted earlier factoring in the internal switch connections in the ign off and emg positions you will see what I mean

Could be that the original ignition switch is not working properly and hence a previous owner bodged the wiring.

A bit on the emg system below.

[Phil C]

Maybe I could buy a switch which would wire up as per diagram, and would fit in the original position in front of the oil tank? Then I could do away with both the buried one and the one behind the rectifier? Would that be feasible for someone of my limited know-how, and if so which switch and where might I get one?  Phil

[Phil C]

Further to my post a few minutes ago, I see in RR vol 2 that the B40 switch used to have an array of pins on its rear which required the correct socket to connect it to the loom, but from '62 this socket became a separate component and was no longer integral with the loom. Connection to the loom was now via bullet connectors on short wires from the socket.   I guess that means the socket was from them on integral with the switch? Does this complicate my idea of buying a new original-style switch? I still wonder if, and hope, it might be easily doable?  Phil

[JulianS]

The early C15 and B40 had the switches directly connected to the bikes wiring loom. The switches were Lucas type 63SA, one for lighting and a different one for ignition.

During 1961 Lucas modified switches and harness. Switches became Lucas type 88SA, the ones with the pins sticking out the back, and the harness had the socket wired to it.

To facilitate replacing defective early switches Lucas introduced sockets with short lengths of cable with bullets attached. This allowed a defective switch to be cut from the harness and bullets attached to connect the replcement socket and switch.

Your original switches would be the 88SA type and your original harness would have had the sockets attached.

Lucas issued a service bulletin on the subject.

Photos of the Lucas bulletin from 1961.

[Phil C]

Thanks very much again Julian. But can  I just check something you say: you say my original harness would have had the socket attached? My bike is  a 1965 B40F. Rupert Ratio vol 2 (p. 305) says that from '62 the socket became a separate component and was no longer integral with the loom. That suggests me that my bike would have had a switch and a socket, both separate from each other and from the loom. The various wires approaching the socket from around the bike would have bullets and snap connectors attached, to which short wires from the socket, having bullet connectors, would engage, and the socket would plug into the switch. Am I right, or am I sadly mistaken yet again? Phil

[JulianS]

No I dont think you are mistaken. I did not give you all the information. Looking at the Lucas parts lists for 1962 on the separate socket with bullets is shown and the harness part numbers change.

So I suspect your harness will have detachable sockets. What does the harness look like behind your light switch in the headlamp nacelle?

Looks like the current production harnesses come with sockets attached.