Intermittent starter/lights problem

[crushedlizard]

Hi, The other day my lights cut out whilst riding (at night!) and the following morning I was unable to start the bike. When I pressed the starter motor I would get a soft 'click' coming form near the seat area. It would just click once, as soon as I pressed the starter button.
I bumped it fine and after that I was able to start it via the s/motor no probs. I went for a ride and my friend commented that my lights were off one minute and on the next.
This morning the bike started fine. I went to a petrol station and when I went to start it - nothing! I had to bump it again.

I've tested the battery and it's a healthy 12.5-13v standing and when revved it increases to roughly 14v.
Basically the battery and charging system appear to be fine (as are fuses!).

What do the lights and starter motor share that could cause only those items to intermittently fail?
Sadly I couldn't check indicators as that was the last thing on my mind whilst hurtling down an unlit road with no lights! But I'm sure they work when unable to start. Again, I can't comment on the tail light.

Any help would be appreciated as electrics are not my strong point.

Thanks

Josh

[carsounds_dan]

check your earths, check the battery to frame earth etc.

[crushedlizard]

check your earths, check the battery to frame earth etc.

Thanks for the quick reply. I forgot to mention I checked the battery earth (I did this before I started testing voltages etc).
What I didn't do was check the individual earths though, say lights and starter motor. I'll give it a go.

Just strange the way lights and starter motor are affected. I would have thought these two devices would have very little to do with each other. I guess it could just be coincidence.

Cheers

[Northern ANdy]

could be chaffed wires somewhere, those two systems are as independant as stuff gets.