Horn not working

[DanGSX]

Hi guys,

Just got bike back from MOT, but the guys have found that one bulb in my tail light isn't working and also my horns don't work for some reason.

Are these linked? Any idea where I should start looking to troubleshoot this issue?

Many thanks!

[Mick_J]

Simplest thing to do is replace the bulb first and then test the horn, they should not have any affect on each other.  Next thing to do is wire the horn straight to the battery to hear if it works if it does you have a wiring fault if it does not work you have a shagged horn.  Do you have a multimeter?

[DanGSX]

Hey, thanks for the reply.

Yep, I've got a multimeter, so i'll follow your advice and see where I get to. I never knew the horn wasn't working as I never use it. It's an all-weather bike, so may even be corrosion I guess. Just hope it's not the wiring loom 

EDIT: Another question I have...How do the twin horns work? If one goes bad, does it affect the other? Or are they separate?

[Mick_J]

The horns are in parallel so work independently, unplug them and use your meter to check you get 12v at the plug when you press the horn button.  If you do it's the horn if not its a wiring problem.

[Batkwaka]

I haven't checked on the 1400 but on other bike horns I've serviced there is a small adjustment screw which needed to reset to get the horn working.

[DanGSX]

Hi guys, Thanks for the replies as always.

Upon further conversation with the guys at the garage yesterday, they told me they did a quick test with a multimeter and said only one horn seems to be getting power coming through, while the other one doesn't - Yet both of them fail to work. Probably one dead, one with wiring issues, but i'll check myself this weekend when i've got more time.

Also, the tail light issue: Checked it myself and it looks like when the running lights are on, only one side of the cluster lights up, but when you press the brake, both light up brightly...Pretty sure I was told they're dual filament bulbs, so I believe I would be correct in thinking that perhaps the smaller filament has gone bad in one of the bulbs? Ordered new ones anyway.

[Speedy1959]

Yes they are dual filament.
In my case one of the brake light filaments was shot ( pointed out by my mate)..
I replaced both bulbs !