LCGB Forums

Hello all. How would someone technically inept, test a series 3 regulator? She's running lovely, just no lights, no horn (oo er)and sip speedo packed up. Cheers

Is this 12v AC system, or a traditional 6v system?

What makes you suspect it is the regulator?

Do you have a meter? If so, have you tested the output from the stator (often a yellow wire)?

If its a 12v regulator the easiest way is to substitute it for one that works.

Tried Ofgem?


Sorry!

Easiest way if you haven't got access to a voltmeter is with a light bulb of whatever voltage 6 or 12v If you can solder a short leanth of wire to the outside of the bulb and the other end to earth and a 2nd wire to the contact on the bulb you can go around connecting it to different points to see if you have a voltage or not. Check the input of the regulator from the stator, don't rev it too much as it will be way higher than say 12v, next check the feed to the loom from the other regulator terminal. I would check it with the loom disconnected as a dead short on anything will pull it down. If good connect the loom and the bulb, then move down the bike. A lot of looms take the Brown feed via the brake light switch and horn but I would go strait to the headset. Check everything is still plugged in at the connection block or bulb holder

Thank you all for the replies. Should have said, it's a 12v electronic ignition. I'm thinking regulator, as I've checked the earths and wire connections so I thought a total power failure (excluding engine) may be the regulator(?). Away this weekend so will have a fiddle about next weekend

Could you not bypass the regulator to check lights work/wired ok by connecting the brown from the loom to a 12v battery if you have one handy ?

You can always just connect the 2 regulator wires together. If the rest is good your lights will work. Just don't Rev the nuts out of it or you will loose your lamps. You can get over 20 v unregulated

Will try that MkMonty. Thanks

Hi revvers,
Good advice from MK Monty and Toddy.You could use a H4 car 55/60 watt headlamp bulb(Pound shop used to sell them) to test the output from stator ..connect the wire from stator to one of the outer bulb contacts and earth the middle connector of bulb.This should shine brightly ,the 60 watt load of the bulb will confirm the stator is producing amps (5) as well as volts.Most stators only give 80 watts max.A multi meter is well worth considering ,many under a tenner,for diagnostics an analogue meter is better than a digital meter,as you can see the needle on an analogue move as you flex wires etc that are suspect .You may have a short somewhere so don't forget the brake light switch I had one that had an intermittent internal short that shorted 12v to earth via the metal plunger of the brake switch.
Good luck,
Grandpa

So, went into the garage this morning, bike starts first kick, all lights working! Have a toy run on Sunday so it'll be interesting to see if they go out again and it'll be in the daylight. Lambrettas.......