Yamaha SR 125 Electrical, lights, indicators&Horn interfer

[Guest]

My son's bike recently failed MOT due to: when headlights on (dip or main) plus either side indicators, horn has 2 tone sound. The main beam warning light and neutral green light flicker along with main lights plus brake light.

Inspected all connections, wiring loom, changed flasher rely,recharged battery,same effect with engine running with revs applied. Bike passed previous MOTs owned for 6 years. Believe it to be a bad earth but run out of areas to check. Wattage of indicators filaments 25 W, remain same for time of bike ownership. Horn works fine independently and when connected directly to battery, the main lights still flicker in time with indicators.

Can any one suggest my next step as once passed MOT selling bike to help pay for recent Honda CB1 purchase.

David Gibson

[Stu]

yup definitely sounds like a earth problem to me

you could try running extra earth wires from the earth at the lights to try and narrow it down

[eastanglianbiker]

if you have a set of jump leads and can reach the negative side of the battery hook up one of the jump leads to it and while testing the lights move the now what is a temp earth about and see what happens but it sounds like it could be the main earth from engine to chassis or dirty connections at battery itself

[Guest]

Thanks Stu and East Anglian Biker.

I am travelling back to work tomorrow and not back home until after the Manx TT, but will try your suggestions.

David G

[Guest]

Dear Readers,

Whilst away I got my wife to take the bike to a Yamaha service/sales shop and they reckon it is the charging circuit. As I am away for a few more weeks they will do the job plus MOT for @£200. Yours David