Flashing headlight!

[andyrint]

Hi guys,

Keeway RKS Sport 125 EFI Euro 4

My bike's recently developed a weird electrical problem. When I start it up the headlight flashes! This usually stops after a few minutes but not always. When I rev the engine the rate of the flashing increases and slows down again when the revs go down. Flashing happens of high and low beam. All the other electricals work correctly including the side light.

I thought I might be something to do with the battery as I remove it every night after work (using spade connectors) as I've had 2 stolen. But that wouldn't explain why it worked fine for over 9 mths since I started removing it.

Any help greatly appreciated!

Tia Andy

[Nobby the Bastard]

Whatever is causing it it won't be the battery. With the engine running the charging system will provide as much as the battery anyway.

Does anything else flash. Try pressing the horn when it's flashing
____________________
trevor saxe-coburg-gotha:"Remember this simple rule - scooters are for men who like to feel the breeze on their huge, flapping cunt lips."
Triumph Sprint ST 1050

[yen_powell]

[stinkwheel]

Is it a conventional filament bulb or an LED?
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[andyrint]

Thanks for the replies

[jeffyjeff]

Sounds like the phenomenon is related to either engine rpm or charging system voltage. I would try bypassing the headlight relay (assuming the Keeway has one) and see if that changes anything. At least then you would know which circuit is affected. Does it flash at regular intervals like a headlight modulator?
____________________
History shows again and again how nature points out the folly of men - BOC

[stinkwheel]

Just check the terminals are a good fit on the bulb and are free from corrosion. Might be worth squirting some WD40 in the light switch and wiggling it back and forth a few times too.
____________________
“Rule one: Always stick around for one more drink. That's when things happen. That's when you find out everything you want to know.”
I did the 2010 Round Britain Rally on my 350 Bullet. 89 landmarks, 3 months, 9,500 miles.

[WD Forte]

[jeffyjeff]

[andyrint]

[Easy-X]

If I were to guess I'd say it's some sort of weird earthing issue where the headlights are somehow finding ground via the ignition system. Once warmed up some other path is found by the magic electricity piskies
____________________
Royal Enfield Continental GT 535, Husqvarna Vitpilen 401, Yamaha XSR700, Honda Rebel, Yamaha DT175, Suzuki SV650 (loan) Fazer 600, Keeway Superlight 125, 50cc turd scooter

[MCN]

Broken Bulb. Change the bulb.
____________________
Disclaimer: The comments above may be predicted text and not necessarily the opinion of MCN.

[andyrint]

[Robby]

30V AC would suggest a very unusual failure mode for a reg/rec, where it's neither regulating nor rectifying. It's just passing the alternator output right into the battery.

[jaffa90]

""""Just put my (very old and very cheap) multimeter across the battery terminals while the light was flashing and it's reading about 30v AC."""
What is the reading in DC volts??? 15?

[MCN]

[WD Forte]

[WD Forte]

[andyrint]

[jeffyjeff]

[andyrint]

[jaffa90]

[andyrint]

[jaffa90]

From what you say/state and the electric start works then did you try stinkwheel advice?
Just check the terminals are a good fit on the bulb and are free from corrosion. Might be worth squirting some WD40 in the light switch and wiggling it back and forth a few times too.