classic motorcycle forum

Motorcycle Discussions => British Bikes => Topic started by: phil bsa b31 on August 20, 2017, 06:37:11 PM

Title: Wiring
Post by: phil bsa b31 on August 20, 2017, 06:37:11 PM

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

Title: Re: Wiring
Post by: TGR90B on August 20, 2017, 06:55:42 PM

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.

Title: Re: Wiring
Post by: phil bsa b31 on August 20, 2017, 07:05:31 PM

Thanks that would be great  Phil

Title: Re: Wiring
Post by: TGR90B on August 20, 2017, 08:27:09 PM

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.

Title: Re: Wiring
Post by: iansoady on August 21, 2017, 02:20:01 PM

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).

Title: Re: Wiring
Post by: Rex on August 21, 2017, 03:30:04 PM

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" ;)

Title: Re: Wiring
Post by: iansoady on August 21, 2017, 03:32:24 PM

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.......