Electrical cut out

Strange issue and, as with all things electrical, difficult to know where to start. A sudden and complete power loss; no ignition, no lights. Battery at a solid 12.3 V. It stopped suddenly riding for about an hour; I was 1/2 block away from my destination. Took the seat & side panel off; all looks good. Tried the switch again and no problem. Started up. Lights and signals all working.

I had this happen once before during a fairly long ride. After 10-15 minutes the problem seems to correct itself. Some component overheating?

Suggestions appreciated.

BC

The fact you have no ignition and no lights would suggest either a dodgy fuse/fuse holder or an intermittent earth

And the ignition switch can be an issue too, had all three faults. Stripped out an old harness that had a permanent no power at all issue and the brand new harness had the fuse holder issue 2 weeks later. I now just automatically replace all the old fuse holders and replace them with proper bladed fuse holders fitted with a reset-able 15A fuse. The reset-able fuse is useful as once it blows after a reset you can turn on loads in sequence until it blows again to work out the offending circuit.

Agree that circuit breaker is the way to go. Original glass tube type are
old, hard to find on a journey and quite expensive.

as kommando says the glass fuse can give problems,the contacts can recede into the holder so although the fuse will test fine it will not make proper contact,cheers

Concur with all the above.

FWIW, 12.3v is only around a 60% charge/capacity. If the engine had been recently running/charging system OK, a conventional lead/acid batt should be showing at least 12.6-12.7 (full charge), more likely much higher immediately after charging. The 12.6- .7 would be after sitting 24 hours after last charging and with no load.

if you have the lucas ignition switch with the spade terminals on the back, check the integrity of those terminals. they can come loose as they are riveted to the plate with a copper rivet (hollow) and that rivet is the contact inside the switch. Solder the rivet to the spade terminal, consider ultrasonic cleaning before soldering and get enough heat into the spade to properly melt the solder. My ignition switch crapped out in the fast lane of the A14 at about 80mph.(ok 70 officer) Any Brit who knows that road will know it was a nasty scenario.

kommando said:

And the ignition switch can be an issue too, had all three faults. Stripped out an old harness that had a permanent no power at all issue and the brand new harness had the fuse holder issue 2 weeks later. I now just automatically replace all the old fuse holders and replace them with proper bladed fuse holders fitted with a reset-able 15A fuse. The reset-able fuse is useful as once it blows after a reset you can turn on loads in sequence until it blows again to work out the offending circuit.

Click to expand...

i have also suffered the fuse holder issue on a new harness.
quick replacement with a blade type and no more issues