Dim headlight - '92 Dio 50

[240]

Hi guys can someone shed some advice if possible.
Just brought a '92 dio 50 for my step son.
It has a new battery,it starts well all the indicators and horn brake light are strong and steady but the headlight and tail are very weak.
There is a small increase in brightness when revving the engine.
I checked the bulb it is a 12v 30 watt which is what it should be.
Any ideas you bright sparks?

[FJRider]

There are different bulbs on the market that give small increases in brightness at the same wattage. See an auto sparky ...

[CookMySock]

Measure the actual voltage across the bulb. You might find that is how it's meant to be.

Steve

[slofox]

The glow-worm is on its last legs...get a new glow-worm...

On a more serious note, have you checked the contacts in the bulb holders? All clean? Wired securely? Maybe check dipswitch as well.

[240]

Forgot to mention the tail light is also dim.

[hmmmnz]

the lighting on the dio's runs through its own coil, its not dependant on the battery at all,
eg the lights will only run when the scoot is running,
normally with this sort of set up, its either working or its not, the only possible exception is if there is resistance in the circuit sucking up some of the power.
eg a bad connection, a dodgy earth ect,
get your multi meter out and check the voltage (probably ac volts) and measure the resistance between the headlight and as close as you can get to the alternator (charging coils) is should be as close to 0 ohms as possible

[hmmmnz]

if you want, bring it over to me and we'll compare it to the dio that lives in my garage

[240]

if you want, bring it over to me and we'll compare it to the dio that lives in my garage

Thanks for the offer i may well take you up on that do you know where the coils are?

[hmmmnz]

yeah they are on the side of engine usual place on a bike

[240]

Sorry to bump the thread but i put a voltmeter across the battery and got 14 volts under high rpm so it is obviously charging,someone mentioned to me that it may a separate charge/lighting circuit???

[hmmmnz]

yes its a different coil, its a 2 or 3 phase alternator, 1 of the phases runs the lighting 1or 2 charge the battery and run the ignition
checking the battery voltage doesnt tell you anything as the coil (phase) is sweet, i would say the other probaly are as well, but you might have a dodgy connection somewhere, or a loose earth

[CookMySock]

yes its a different coil, its a 2 or 3 phase alternator, 1 of the phases runs the lighting 1or 2 charge the battery and run the ignition

Could they be rewired so all three charge the battery, and then reconnect the lights to the battery circuit?

Steve

[hmmmnz]

yeah its kind of possible, but i the one that feeds the lights is just part of 1 of the coils, (eg the coil produces say 40v.ac while running and there is a tap of that coil 1/3 the way along it, at that tap its producing 12v ac, hence why when you rev the engine the lights brighten (because the voltage goes up)

so you could just ditch that take off and just connect the lights via a relay (controlled by the ignition switch) fed from the battery, pretty easy to do, a bit of fucking about, but no real dramas

but its probably a whole lot easier to find and fix the fault as i said feel free to come to mine and we'll give the wee scoot a going over and use the one in my garage as a reference if needed

http://s675.photobucket.com/albums/v...t=hondadio.gif