Electrical problem help plese :S

[b0unt1 tw1ns]

Hi people i bought a Derbi senda sm-extreme 50cc last year as a project ive got every thing ready bike running then i hit a problem.
The front and rear lights wont work ive tested the power and theres nothing there so i bought a new regulaor and still theres no power.

If anybody could give me any ides of what it could be it would be much appricated Tom.

[TUG]

Urm, I remember someone having a problem like this but cannot for the life of me remember the cause.

First of check all the fuses an the battery, a bike can run but the other electrics might not function because of a duff battery.

Check all your connections, failing the simple stuff, I would suggest looking into an owners manual for troubleshooting or a workshop manual for indepth information.
____________________
Haz ER-5, innit!

[dolly3900]

Hiya,

First check the battery is giving out the correct 12V (or 6 if it's an older one)

If it is a 6V system, check that you have 6V bulbs as 12V ones will not be bright enough to see.

As the previous answer said, check all the fuses to makesure they are in and OK.

Check both sides of fuse for voltage, if only 1 side, then dodgy fuse/holder.

Check that there is a voltage at both sides of the switch when on and only one side when off.

If there is nothing at the switch at all, this would indicate that the connection between the battery and switch is broken.

If the fuse is battery side of the switch (unusual, but sometimes), then would indicate break between switch and fuse, if straight to battery, then break between switch and battery.

If OK at fuse and switch, then would indicate a break between the switch (or fuse) and the lamp itself.

If no lights are working, then it would sugest that the issue is between the switch and where the cable splits to feed the front and rear lights.

All that said, I would also sugest that firstly you check that the bulbs are not blown (have had two go at once before).

Also, check the connections within the bulb holders for corrosion as if they are dodgy, you will have no power to the lamps.

Finally, I would have a look at the earthing on each of the lights as a dodgy earth could cause pretty much the problems you have.

Try dis connecting both lamps and then test each one seperately as a bad connection on noe, could kill the other one.

With the rear especially be careful as there will be three connections, one for rear light, one for break ligh and a common earth. make sure they are in the righ tplace as you could have some weird issues with that too.

Hope that helps.

Mike

[at106]

Have you tested the lights while the engine is running? As on some bikes the power for the lights comes from the stator plate behind the flywheel meaning if the engine isn't running the lights wont work.