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Oh the joy, been plagued by the hassles of dim lights on my 6 volt DC system, she starts great and runs like a charm but...for some reason the lights have got worse all of a sudden (yeah I know they're 6 volt but normally pretty decent) now I've checked all the earths, replaced connectors, even swapped over to a new scootopia bulb holder as the old one was kind of rough. Still shite, checked the wiring into the rectifier and like wise given a service and clean. I know the lighting off the stator is proved by the brown wire , is there a way of testing it without a tester? ( never figured out how to use those things) also would a knackered ignition switch have a effect? its the original one with the scoot so a bit old and worn, cheers Paul

flywheel might require re-magnetizing......

MickYork wrote:flywheel might require re-magnetizing......

thought that myself but its just happened all of a sudden, surely that would be a gradual thing?

Yes a knackered ignition switch would cause the problems along with a multitude of other problems including a faulty battery.
You either have- a high resistance joint ( including the stator plate earth) something dragging the whole system down or poor supply power.
Bypass the ignition switch streight to the headlight/back light circuit and see what happens that might give you an idea if it's the ignition switch.
Try it without a battery or get a loan of a mates, faulty battery's can cause excessive draw on the system, as can a failing bulb.
Try taking the bulbs out one at a time to see if this makes any difference.
The only way to really test the test the supply is to use a meter.
The brake light doesn't go through the ignition switch- so if that pretty good then

Meds wrote:Yes a knackered ignition switch would cause the problems along with a multitude of other problems including a faulty battery.
You either have- a high resistance joint ( including the stator plate earth) something dragging the whole system down or poor supply power.
Bypass the ignition switch streight to the headlight/back light circuit and see what happens that might give you an idea if it's the ignition switch.
Try it without a battery or get a loan of a mates, faulty battery's can cause excessive draw on the system, as can a failing bulb.
Try taking the bulbs out one at a time to see if this makes any difference.
The only way to really test the test the supply is to use a meter.
The brake light doesn't go through the ignition switch- so if that pretty good then

Thanks for the advice, doesn't running the bike without the battery damage the stator and not advisable ? also how would you by pass the ignition switch? many thanks Paul

try the brown wire in your headset connected to one of the headlamp connectors, just a length of wire to bridge the two, just to see if its any brighter, dont turn on the ignition on and that will give you an idea what the problem is, no change in brightness would mean you have low output, if its brighter then the problem could be your switch.

Hi Holty
Some useful advice here.Could your regulator/ rectifier be suspect and does it have a good earth .Also rig up a temporary earth wire from head set to frame.
viewtopic.php?f=10&t=7204

Grandpa

A useful test for high resistance is to set your meter to volts (AC or DC depending on your system) and place your probes on either side of the joint, connector, switch or wire that you want to check. You should expect to see ZERO volts, any reading at all indicates some level of resistance (volts drop).

We really need to know what electrical system you have, traditional lambretta-modern lambretta- what rectifier/regulator as some of them need a battery to work correctly.
To bridge out the ignition switch completly we need to know what loom/ignition you have
Please don't take this the wrong way
if you can't us a meter or draw/ use a wiring diagram then it may be better to get someone who can use that kind of kit to help you as the fault could be a multitude of problems.
Did the fault apear after changing bulbs, doing maintenance or cleaning it?

Meds wrote:We really need to know what electrical system you have, traditional lambretta-modern lambretta- what rectifier/regulator as some of them need a battery to work correctly.
To bridge out the ignition switch completly we need to know what loom/ignition you have
Please don't take this the wrong way
if you can't us a meter or draw/ use a wiring diagram then it may be better to get someone who can use that kind of kit to help you as the fault could be a multitude of problems.
Did the fault apear after changing bulbs, doing maintenance or cleaning it?

as quoted at the start - its a 6 volt Ducati DC set up on a SX , standard wiring loom with all the gubbins , the fault appeared after I took my speedo out to replace a cracked lense for the MOT (got a additional earth lead fitted to the speedo as per sticky's book) everything has been checked in the headset and is/ looks fine so maybe something else has suddenly decided to play up , the regulator/rectifier is fine, a NOS unit I bought from scooter restorations a couple of years ago and the fuse and battery charging is fine. Checked and replaced (where necessary) all connectors and earths and checked the loom and back light units. So...hence my questions about possible de-magnatised flywheel in the other thread , could a failing coil could be to blame? going to check the power out of the brown wire. Yep I don't know my way around a multi-meter, tried several times but they are hardly a obvious bit of kit. Thanks for the replies and tips. Paul

You can disconnect the battery for test purposes.
I would start by looking at the headset- remove the speedo lamp and bulb holder, it can short out on things inside the head set and see what happens.
Can't help with the flywheel demagnetisation, other than swap it for a known good flywheel.
It's unlikely the coil will cause the problem as its fed from a completely different circuit- and you say it starts and runs ok.

Meds wrote:You can disconnect the battery for test purposes.
I would start by looking at the headset- remove the speedo lamp and bulb holder, it can short out on things inside the head set and see what happens.
Can't help with the flywheel demagnetisation, other than swap it for a known good flywheel.
It's unlikely the coil will cause the problem as its fed from a completely different circuit- and you say it starts and runs ok.

thanks for the reply , doesn't running the engine without the battery damage the stator? will give the other things a look. Paul

Disconnect the bulb from the bulb holder in the speedo and try but don't rev it too high as you might well blow the rest.