BTH Head Lamp Lightning Switch terminal description.

[Pseudotsuga]

Hello ,
I am Christian and I am working on an E32.

The BTH Headlamp wich is mounted has an Cable Connector.

( Hope you understand my " perfect " english)

The switch is working and I rewound the Ammeter yesterday with success.

No I have not enough knowledge to take all cables on the right terminal ,
cause off I did not know the exact meanings of the Letters of the terminals.

Can anybody help me with a drawing or a list with the descriptions ?
The switch has 4 positions , Off , C , D, F.
What does it means ? C = Charge ? .......

Thank you very much for your help ,
and I wish to all a happy new year

Christian

[EW-Ron]

Aren't old electrics fun !

OCDF  is Off, Charge, Dim, Full   as you suggest.

This 4 position switch is an improvement over the previous 3 position, 
which was always charging the battery - and thus often boiled it.
Charge will bypass the resistance wire/coil there.

Dim will supply power to the small auxiliary (pilot) light, and Full will supply power to the main globe.
You may or may not have a dipswitch on the handlebars, to a 2 filament main globe.
Such may be an update to the earlier system.

I'm afraid I've not met your actual BTH switch.
There are many words on this forum about them, but no actual makers info/schematics ?



 

[EW-Ron]

Charge will bypass the resistance wire/coil there.

Only to be used when you know your battery is low. ?

If you feed power into your switch, you should be able to figure out where
power is coming out of it, in various switch positions - and wire it accordingly.
This may require some trial-and-error. And maybe lots of it !

It will be a bit simpler if someone has a factory diagram of this.
Hopethishelps.

P.S. The VOC  has this for a mid 30s BTH system.
Maybe some is common with your arrangement. ?
https://www.vincentownersclub.co.uk/attachments/diagram-pdf.22635/

There must be an equivalent diagram somewhere in the Douglas world.

[Pseudotsuga]

Hello EW-Ron,

thank you very much for your help.

Everything is fantastic what I do not know !

Now I can complete the work on the Lamp.

The Vincent BTH description is very helpfull.

Thank you

Christian ( who now can kill the copper worm )

[Pseudotsuga]

Hello ,

I am now finished with the electrics and everything works as it should.
For those who are interested, here is the wiring  and a few pictures with the names of the terminals.

This is done with a BTH Headlamp with a 4 Position switch and no high beam .

From : Generator to : Cutt-off Switch to : D
Color : most yellow

From : Taillight to : T
Color : green

From : EARTH to : Housing Lamp ( or if the lamp has a plug connection :
to the long pin that connects the plate .)
Color : brown

From : Batt+ to Ammeter to: F
I tried to connect Batt+ to the B+ Terminal but this take noch effect .
Color : red

The Terminals B. and B+L must closed by a bridge.

Thats all.

I pushed the alternator with neodymium magnets using the instructions from the forum here.
And it works perfectly.




If the lamp has a plug connection, the cables must of course be looped through.

All in all, I think the design of the electrical system is very nice.



When it's a bit warmer and I can ride, I'll do the tuning of the lamps. This means selecting the power of the bulbs so that the ammeter is slightly positive when the light is switched on during normal driving.

Best regards

Christian