This is getting a fun thread !
Right - chris99 - my judgement as a qualified electronics engineer is that you are obviously interested enough in fixing something like this yourself to go and buy yourself a nice little multimeter.
What that will give you is hard information ... (note that lots of guys have been quoting voltages) and then you can judge whether what you are seeing makes sense from the NUMBERS.
Just remember what I said about poor connections - they can be anywhere a bolt is or a connector is or a crimp ... and they can all add up in a small way to stop something working how you expect.
Lotsa 'big' problems are caused by lotsa small problems added together, and you really really dont want to pay the guys in garages to find a dodgy crimped connection !
When you have a multimeter you can also compare voltages with something that IS working ok - like a mates bike or your car !
(If you were closer I'd come over and put you out of your misery !)
</rant>