A65 condensers

[Talisker]

1968 A65 Tbolt , purchased in bits. I am starting to put it back together and today was wiring day everything was going well until I got to the condensers (under seat in small box) my Lucas diagram doesn't show them so my question is how do I connect them and are they positive/negative sensitive?
Regards Jim

[AWJDThumper]

Basically, the +ve terminal on each coil has to be wired to its contact breaker and condenser in parallel - this could be via two separate wires or the wire from each coil split at some convenient point. The other side of each condenser needs to be wired to ground. The condensers are electrolytic capacitors and only work one way round - if designed for the A65, the cases will be the earth contacts.

[AWJDThumper]

A picture sometimes makes it clearer!

[Talisker]

Thank you much appreciated
Regards Jim

[Nanonevol]

I didn't think condensers were polarity sensitive only by what I've read in forums, not ever tested by me.

[berniej]

Ordinary capacitors (=condensers) aren't but electrolytics are.

Those that are specifically designed to fit on points plates or outside a distributor often use a single lead and the case as the two terminals so can't be easily reversed.
If they were electrolytics then a change in polarity of the bike electrics would also require a change to the capacitor - I didn't think these type are electrolytics but not 100% certain on that....

Cheers,
Bernie

[AWJDThumper]

I retract what I said about them being electrolytic - they have the form of electrolytic capacitors I am used to and I was assuming the capacitance required was in the micro-Farad range which would require it to be electrolytic. However, I can now see the points only 150 nF capacitance which is low enough to use a less exotic dielectric between the foil plates. They are therefore polarity insensitive.

[Nanonevol]

Thanks for explaining what I knew only as hearsay.

[Talisker]

OK I am getting there but have spent much more time on the headlight than I should. The engine was rebuilt for me and the wires coming from the points are marked right and left . I assume this is to the corresponding coils?.
Thanks for your explanations so far.
Regards Jim