[solved]Electrical Power Issues - No Power

Hi all

I'm looking for some help, After 8 yrs of faultless service my cb500 failed to start. heres what happened:

last night I switched the ignition on and experienced normal indications, bright dash lights and headlight. I pressed the starter and the engine startedto turn over with normal vigour then all power failed, no lights at all and no more turning over not a bean as if the battery wasn,t connected.

so today I checked the voltage of the battery and got 12.5v checked all the fuses(3x10amp 1x 15amp and the 30amp) all good, I then checked the supply to the ignition switch plug inside the headlight and got 12.5v. I checked continuity through the ignition switch and all was good.

then I reconnected the ignition switch and checked for voltage at the fuse terminals and got 12.5v with them removed and ignition switched on. I have also checked for voltage at the reg/rectifier and got 12.5v.

so again my symptoms are that with the ignition switched on it is like the ignition switched off or battery disconnected, no lights(neutral sidestand,oil or even movement of the temp dial  no turnover and clicking noises at all. looking for some further suggestions

Many thanks

Mike Impey

At first guess you've got a dodgy connection somewhere. Starting pulling plugs apart looking for corrosion, bright green contacts etc. As everything dies, the first place to check will be the battery terminals. Make sure the leads are bright and shiny as are the battery terminals.

Sounds like a dodgy connection. Check the wiring
 on the R/H switch unit on the handlebar. If it happened when you pressed the start button it might be to do with that.

Stooby2 wrote: ......As everything dies, the first place to check will be the battery terminals. Make sure the leads are bright and shiny as are the battery terminals.

My money would be on this.

If the terminals are ok, check also the connection where the battery is earthed to the bike. This caught me out before on another bike.

Thanks guys in the end it was the battery
 
The battery voltage threw me a bit showing 12.5v, but after checking all the wiring i went back to the battery and found when the ignition was switched on the battery volts then dropped to 1.6v not able to take a load, battery replaced now all good.
 
on the plus side whilst checking my bike for wiring faults i found two chafed wires one by the rear brake switch where it passes up through frame and the other on the headlight loom entrance which are now repaired and protected many thanks
 
Mike