bsa c11 1939 dynamo problems.

[bsajoe]

Hi, i have just been fixing up my first BSA, It is a (im told) rare c11, in the fact that is has a split tank and the oil is return not through flow. not sure how rear it is exactly but, i like it!! anyway , i am not getting any charge to the battery. It is a new battery, and i have had a look at the dynamo, it all seams clean and the wire is all looking ok, but i dont think there is a charge coming of it.  I can ride the bike on a full battery but it just runs dead, any ideas tips, i was told to maybe sort the connect between the out put and that might shock it into working! or that is is the cut out??
any help , thanks
jamie

[Revband]

Hi Jamie

If the dynamo has been unused for a long time then it is likely that the field coil has lost its residual magnetism, this is easily cured, disconnect the D & F wires from the dynamo and if the bike is negative earth use a wire to connect the battery positive to the F connection on the dynamo, if positive earth connect the negative battery to the F connection, just touch the wire on for a second or two and this will re magnetize the field coil core.

Only do this if it is a two brush Lucas type dynamo, if it is a MIller let me know as the process is slightly different.