Lucas E3L Dynamo Wiring

[adrianwebber]

Dear All,
This is for a 1958 350 NH in bits....

For some reason 18 years ago when I dismantled the bike down to the last nut and bolt I did the same withthe dynamo... I painted the body and that was as far as I got. Now, as it's too cold in the garage to work on the rest at present I thought I'd re-assemble the dynamo and replace the commutator end bearing.
It's back together but I realise I have no idea which way round the various connections should be made. Amazingly there is almost nothing detailing this on the Internet (that I can find anyway!).
Does anyone have a diagram that clearly shows what goes where please?? There are 2 terminals labled F and D. At present one of the leads coming from the windings is attached to "D", the other to earth on the commutator housing.

I also have no idea about even the basics for this bike. My sole reference is a 1999 Draganfly catalogue. I do not even know which polarity my bike should be... I cannot find a Workshop Manual for the later bikes.

All pointers welcome..

Many thanks,

Adrian
Bristol UK

[will_curry]

Hello Adrian,

There should be 4 wires inside the dynamo: 2 from the field coil right inside and 1 from
each of the two brushes. One of the brush wires goes to the 'D' terminal and the other is
earthed to the bearing housing with a little screw. Also earthed to the bearing housing
is one of the wires from the field coil. It should be the one with the sleeve but it doesn't
(usually) matter. The other field coil wire goes to the 'F' terminal. Set up like this there
is a 50/50 chance that the dynamo won't turn in the correct direction and so won't
generate any output. If this is the case swap the two field coil wires over. If the dynamo
generates but generates the wrong polarity - negative earth in stead of positive -
disconnect the 'F' and 'D' leads from the dynamo to the control box and touch a wire
from the live side of the battery to the 'F' terminal on the dynamo. Put things back
and everything should be fine.

Will.

[adrianwebber]

Hi Will,
That's great, many thanks. I have of course wired the thing up backwards then - there was a 50/50 chance I'd get it right.. Troublle is I'm going to have to take the brush end back off as one of the wires from the inside is either shorter or has become trapped. As the new bearing is a really tight fit on the shaft this will prve entertaining!
Thanks again ..

Adrian
Bristol UK

PS does anyone know what polarity a 1958 350 NH should be ??

[will_curry]

Hello Adrian,

Positive earth from 1951 onwards.

Will.