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I'm not appearing to have any luck at the moment. After fixing the brakes I was in the garage a few nights ago and put the keys in the ignition and switched on whilst the Optimate was still connected up. Stupid mistake. One of the 4amp fuses blew and also the tail light/number plate light and the neutral light and the bike is totally dead when the starter is pressed. I have put a new fuse in and traced the starter/neutral light problem to the starter relay which is out so a new one will fix that. However, I cannot track the rear light/number plate light problem. The brake light comes on when the front and rear brake pedals are operated so it's only the rear light and number plate light that are dead. All the little black relay's (4 in all) seem ok. There are 2 in each electrical box on each side of the bike. I think the problem may be the flasher box....the larger black box on the right side electrical box ? When I press the indicators they flash ok but there is no clicking noise given off and they go on and off in silence. I can't remember if there should be a clicking noise or not. Has any electrical expert any ideas as to what I've done. The fuses and relay boxes should protect the system so hopefully I hav'nt damaged anything more complicated/expensive.

Thanks

Come on guy's someone must have an idea as to why the rear light and number plate light are not working. All fuses are ok. I need someone to verify if the flasher relay makes a clicking noise when operated. Mine is flashing the indicators but is silent. There is a common brown wire from both the rear light and number plate light which goes into the flasher unit so maybe the circuit is broken there. Anyone have any ideas ?

Thanks

as a quickie - the tail light is one of the few things that is de-powered by the load-shedding relay (the load shedding relay is part of the starter relay - it cuts all unneccessary power when you press the starter) So, it might be affected by your zapped starter relay. Just a thought, have gone and fetched a beer and my beano/haynes manual.

right,
1. the 12v to your tail light/number plate light is common with the 12v to your sidelight (in the headlamp) - so check if that's coming on with the igntiion & ;ights switched ON. If it does, (and the tail light doesn't) then you've got a break in a wire or connector that feeds the back lights.
2. the tail light/number plate light can get its 12v from 2 sources: the 'normal' source which is via the load-shedding relay / light switch etc, and the PARKING source, which is via the 'P' position on the igntion key (the one you can switch it to and remove the key - it leaves your parking lights on whilst you go shopping) This source is direct from the battery - try it - if the tail light works, then you've got a non-working LS relay (assuming all your fuses are okay).
More info available...

your starter relay is switched on both sides - it gets its 12v from the battery via the ignition switch and the starter button - there's no fuse to worry about. On the other side, it gets its 0v from either of two sources: either the neutral switch (which has a diode in series with it), or from the clutch switch, so long as the lever is pulled in.
Sooo, you could try the starter button with the clutch lever pulled in - if things happened then, it means your relay is ok - and the fault is in one of two areas: either your neutral switch is knackd (in which case your green light wouldn't be on), or your diode is zapped.
Apologies if some of this is obvious (eg pulling the clutch lever in), on the other hand, I think it's safe to say that your rear light problem is related to your starter relay problem. Dunno why the starter relay (or diode for that matter) would get zapped by an Optimate though.
Tried me best.

And finally......have you checked the bulbs?

Thanks r550's. I was looking at the wiring diagram and saw that the tail light ran through the side light so I popped out the bulb hoping that it would be blown. The filament is intact but I can't get the thing to come on. I've got the lights on and also tried turning the ignition key to the parking position but still the sidelight will not come on. The starter unit is totally gone though. I pulled the cover off and one could see the little swith which connects the starter so I pressed this to the connected position and the starter goes into operation so that relay needs replacing. I've tried swapping all the other little black relays around to no avail so I don't think its the power relay or any of these. I did'nt realise that the tail light had any connection with the starter relay so I think you might have hit on the problem. All the bulbs in the system are ok.

scotty wrote: I did'nt realise that the tail light had any connection with the starter relay so I think you might have hit on the problem. All the bulbs in the system are ok.

Don't the lights temporarily switch off when the starter is pushed in during normal operation? I think they do, so they must be linked somehow. The only time I've had the tail/sidelight go OS at the same time was due to a break in the ignition wire from the ignition switch.

Jason

...nearly there!
If you've got a wiring diagram (is it the Haynes?) then look for the 'Load Relief Relay' - the relay coil is energised by the green wire connected to it on 86, this green wire is 12v from the ignition key ON switch. The relay coil's 0v comes from the black wire connected to it on 85. The idea is that the LS relay energises when the ignition is switched to ON, and this gives you 12v output on 87 - for the tail lights etc.
This is the crafty bit...check out where the black wire on 85 goes to - it's actually connected to the signal wire to the starter motor relay coil (which gets 12v when you press the starter button) this means that, when the starter button ISN'T pressed, this black wire sinks to 0v through the starter motor relay coil (cos the other side of the starter motor relay coil is connected to earth) hey presto: the LS relay coil, (which only needs a small current for it to work) has got a good enough 0v connection, it energises, and your lights work. Of course, when you press the starter button, the black wire gets flooded out with 12v and the LS relay coil no longer has a 0v connection so it de-energises.
Phew, do you think you've located the LS relay?