Testing a Lucas 49072 Rectifier

[A10 JWO]

Found a rectifier in one of my boxes, how can I find out if it works correctly. 12 volt Pos earth. Thanks.

[a10gf]

Feed it with 12v AC, and measure if 12v DC comes out :O) Should be easy ...if having some AC source available.

Is it this > http://www.sparesforclassicmotorcycles1.co.uk/genuine-lucas-49072-positive-earth-rectifier-bsa-c15--ww10135-976-p.asp
am guessing the yellow must be the AC in.

[Bsareg]

This looks like a selenium rectifier. Although it looks good cosmeticly, this type can age and become leaky. When new they were not as efficient as a modern silicon type. Ok for originality but not for reliability.

[A10 JWO]

Thanks lads, that looks like it. Will look into the more modern one, just spent a few shillings on a complete Boyer kit with dual coil and heatsink. Might as well go the whole hog.

[chaterlea25]

Hi JWO,
As you have bought the Boyer kit it would be a very good idea to invest in a quality combined rectifier regulator
Electronic ignition and old rectifiers / zerer's do not marry well 
Add extra earth wires from the headlamp and tail light to the main earthing point on the frame where the battery and reg are also earthed

John

[A10 JWO]

Thanks John, on your advice I did that this afternoon. I have fitted a new modern rectifier today, but will look at the regulators. Must admit it looks like the Starship Enterprise under the seat. May need a smaller battery due to possible lack of space ( that may be another thread. )