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Two problems possibly connected:

1) with the key in second (ie lights on (5 pole switch - 1977 Strada)) position the bike stopped charging.

2) having checked wires to switch and fuse block bike then wouldn’t turn off ie runs even with key out.

Any thoughts out there?

Cheers

Lewes96 wrote: ↑04 Aug 2021 16:20 Two problems possibly connected:

1) with the key in second (ie lights on (5 pole switch - 1977 Strada)) position the bike stopped charging.

2) having checked wires to switch and fuse block bike then wouldn’t turn off ie runs even with key out.

Any thoughts out there?

Cheers

Taking the second point first.
The ignition switch in the off position shorts the green wire to the blue wire. In both ON positions it disconnects green from blue.
Conclusion: If the engine continues to run with key in OFF position then the continuity of the green to the switch or the blue which goes to earth is not there.
The two problems can be related.
The not charging situation may be because the switch is incorrectly wired or faulty. The regulator must have 12V connected to the brown terminal or it will not charge. Check that the red (from Battery) connects to brown (to fuse box and hence regulator) in both ON positions.
You need to check every connection to/from switch with respect to the wiring diagram, also check each position of the switch that the connections internally are correct.
Hope that helps

Mark

Dang you are good at this stuff Mark. I remember you helping me!

Found the issue in poor earth so switch not earthing! So all good there. In terms of connections to regulator the wiring is as per Blue service manual - see pic - so brown from fuse box to regulator as required I think. And red from battery to fuse box. Cheers

Glad you got it sorted. Common wisdom seems to be that you can't go wrong with extra earth points, and that it's always worth checking/cleaning terminals and bolted connections, especially if they've not been looked at for years.

Although my sport wan't too bad, it has most definitely benefitted from an overhaul of the fuse box (taken apart, all terminals cleaned up, loose rivets drilled out, bolted and soldered for good measure, especially the terminals which connect to the fuse holder- these often go floppy and give at best a weak connection.)

I also ran extra earths from the main crankcase earth via the starter relay bracket on the frame to the back of the regulator case, and another one up to the junction box under the headstock and into the headlight so the ignition switch, lighting and other electrical circuits have several good routes to earth.

Also, don't forget the importance of the diode (fitted the right way round!) inline on the green wire to the ignition switch- this diode prevents a switch failure from putting 12V into the transducers, which will fry them.

Diodes and their rating, are a bit of a mystery to me Tom,
Can you recommend one, or post a link to "the kind of thing" on Fleabay Vehicle Wiring Products or similar. Shielding elderly Transducers definitely seems a worthwhile task

Look for any of the 1N400- series, they're dead common. 4001 is up to 50V, so should be fine, 4007 is 1000V but still cheap as chips (which they are...)

Ming wrote: ↑01 Sep 2021 06:42 but still cheap as chips (which they are...)

If you don't do this do you get fries with that? Asking for a friend.

I won’t profess to know what diode should be fitted or how to spec one. Ming sounds like he knows what he’s talking about though.

All I can say is my bike has one of these fitted. Works fine although I suppose you wouldn’t really know until you had a switch issue!

https://www.altecautomotive.co.uk/10-a ... 5466-p.asp

That is fine, though a bit ott for it's purpose. Here's a link to 1N4007s. Only 1 amp, but they are used to stop any dc voltage getting to the transducer, so don't pass much current anyway. https://www.ebay.co.uk/itm/322166839333 ... Swv0tVL9TB
Edit - the 'bar' ( -|<- ) on the diode should be towards the switch, so that it blocks dc going to the transducer.