Triumph 500 Tiger 1967/8

tom wilson · Aug 27, 2020

Hi a friend of mine has a Triumph 500 Tiger SS 1967 E registration Positive earth, it has the original 12v Lucas Rectifier fitted (plate type, 3 wires plus earth) its over charging. I would like to fit an up to date one, any one can recommend who sells a decent one at a low price? many thanks in advance

EJT · Aug 27, 2020

Can’t help with charging system upgrade as I use the original system. However……
I would check the zener diode, which actually controls the charging voltage by shunting excess voltage to ground (the rectifier just converts the AC alternator output to DC). The diode is under the left side panel on a 67 or under the headlight in a finned heat sink on a 68. Make sure it is grounded properly and the wiring is intact. This might help…….

https://www.classicbritishspares.com/blogs/news/lucas-zener-diode-test-tech-tips

feckless · Aug 30, 2020

you could fit one of these, if its overcharging it sounds like the zener has gone.
www.ebay.co.uk/itm/SINGLE-PASE-12V-160-WATT-RECTIFIER-REGULATOR-FOR-CLASSIC-NORTON-TRIUMPH-BSA/392145572963?hash=item5b4db29463:gecAAMXQkl9RaR9w