Morning Beamers!
Whilst the cylinder head is away being sorted, I have begun work on the electrical system. The book's diagram is complex so I have converted it (for the Model 8) into a colour diagram. Could you have a look and see if I have got anything wrong or need to add?
Have a great weekend
The red dotted line from H goes to the dip switch but should not go to the headlamp bulb.
L comes from dip switch and then to low beam OK.
N comes from dip switch and then to high beam,not shown on your diagram as far as I can see.
apart from that it looks OK..John
Thanks John - how does this look?
looks like it matches the diagram in the book,,,unless you have a panel tank ;D :'(..john
My headlamp switch has a nifty little wiring diagram incorporated:
(http://i43.photobucket.com/albums/e398/iansoady/bike/Sunbeam/light%20switch/IMG_2187_zpsiu6rifo8.jpg)
Your diagram looks pretty good to me.
What had me confused for a while is that the three-brush dynamo has the field windings earthed (via the headlight switch and, for half-charge purposes via the resistor incorporated within it). I'm more used to the field windings being provided with a positive feed as on post-war dynamos.
I did measure the resistor and it came out as 8 ohms if that's of any interest. I was advised to convert the dynamo to 2-brush operation but preferred to try to keep it original. We'll see how that turns out!
I have discarded the cut out contained within the dynamo and bypassed all the half charge resistor and sprung copper contacts. Instead I have added an external MCR1 (which appeared later in t he thirties) regulaltor. I was really forced to do this because of the quality of the H52 headlamp bits bits but Ian was lucky he started with good stuff. I worked out a different wiring connection so that the half charge switch position does nothing. I think I would have made this mod had I owned the machine in the later thirties on the advice of my father who worked at Joe Lucas (he designed the Alto horn)
I think if I was going to use the Sunbeam as an everyday bike I would probably do the same. It just seemed that keeping it original was more of a challenge!
One thing I have done with all my restorations is to use an earth wire instead of relying on the frame. If you have done a good job on re-painting, you will have created some lovely insulation! You could, of course, take all the joints back to bare metal and use some conductive paint, but I think the earth wire is more reliable. It is very easy to disguise if you are concerned about originality.
P.
Agreed Paul, and I always do the same. I rewired the Model 10 using all black thinwall 16.5 amp cable from Vehicle Wiring Products, encased in their braided sleeving: http://www.vehicle-wiring-products.eu/product.php/514/braided-sleeving which is not original but looks the part and doesn't stand out like harness tape or other modern types.
It's also important to ensure that the engine / dynamo etc are well earthed - my magneto actually has an earth connection which I've used to take a wire back to a common earth point inside the battery box.
I have to confess that my search for authenticity has faltered there and I've used chocolate strip connectors although they're invisible till the top is removed.