Wiring

[phil bsa b31]

Hi I have a bsa b31 rigid 1948 dose anyone have a wiring diagram also will this be positive earth  thanks Phil

[TGR90B]

I can post a "C" series diagram if you like; it should be similar. Switches may vary, but it will give you a guide. Positive earth almost certainly.

[phil bsa b31]

Thanks that would be great  Phil

[TGR90B]

Phil, my C stuff is no good as it's all alternator, but I did find this in the Gold Star book. If you want to PM me with your email address, I'll blow each one up to A4 & send them to you.
Dave.
P.S. Looks like I could have been wrong on the positive earth with an early bike.

[iansoady]

I think positive earth came in around the early 50s. TBH I hate it as I'm easily confused.......

If it's a magdyno bike with CVC then virtually any British wiring diagram for the period would be pretty close. Eg this one: http://archives.jampot.dk/book/Owners_manuals/1951_Matchless_singles_Manuaul.pdf (note negative earth).

[Rex]

Pos or neg earth.....it's no different in how it works.
I thought it was only Yanks who threw their hands in the air at "the wrong ground"

[iansoady]

I don't throw my hands and of course you're quite right. It's the momentary brain fade when I'm connecting the battery.......