Why won't my headlights turn on?

Fastasfox: I have a 2003 ZX-6R and I can’t get the headlights on. The lights should turn on when the engine is fired up and I have looked at the bulbs, connections, new battery (on a battery conditioner) and fuse box (replaced with a used part).

The battery was duff (wouldn’t hold a charge) so I got a top of the line new one thinking that the headlight relay (inbuilt into the fuse box) required a strong current to operate.

However when I turn the ignition off and then on again and fire her up they won’t come on. It’s doing my head in.

smidget: Hi FF, have you checked the light switch for good contacts? Remove the switch, clean contacts, test circuits with OHM meter, if OK refit.

Either that or have you got another switch you could try, I would also suggest trying the same with the relay.

James600zx: I’ve half an idea that if your charging system is playing up and you’re intermittently running on battery-only perhaps there’s no juice left for lighting?

Check the regulator/rectifier connection. When you return from a ride does the battery conditioner have any work to do?

smidget: Good shout on reg/rectifier. Fastasfox, are all the connections good to the ignition switch?

Paul49: Could this be a fault inside the ignition switch?

fastasfox: James, I have run my meter on the battery and given my bike a rev and the volts go up to around 13.5, which is about right.

I have no switch other than high/low, because the lights are automatic and the sidelights are on but not the main lights.

When you turn the ignition on it does a systems test and no faults come up. I’m going to have a look at the reg/rec just to see if all is ok.

Beyond that, I will take her to Peterborough Kawasaki. I will keep you all posted, thanks for your ideas.

jaffa90: A quick question for now. Does your pass or headlight flash work when you’ve no headlights on? Also do your parking lights work with your key after steering lock position?

Smidget: Reading your first post it leads me to think that there is a bad contact somewhere within the lighting system, so I suggest that you check and clean all the earth connections, the same with the high/low switch contacts (sorry, I didn’t explain myself better in my first post), and the ignition switch.

Jaffa makes a good point of the flasher switch. A couple of hours doing the simple bits may cure the problem and save you a few shillings which you can put towards that 2010 model you are drooling over.

fastasfox: Thanks for all your help. I just picked it up from Peterborough Kawasaki.

It only took them 1 1/2 hrs to fix (that¹s still over £80). It turned out it was a wire that had come loose in the alternator and had shorted out.

The problem I had was not knowing where and when the lights get their power as they don’t turn on until the engine is running.

But then like most of you I’m only an amateur. Thanks again for your ideas.