Would any electricians like to review this circuit schema and pass comment?

I'm also thinking of adding a second relay, activated by high beam, to by-pass the 'kill switch', so the DRLs (Daylight Running Lights) always come on with the high beam.

A few things I would change.
There is no need for the fuse after the Relay You are not going to gain any current going through the relay, Just the one from the Battery will suffice.

I would move the switch to in between the side light and the relay save you running the wiring back from the lights up to the switch you can Earth it to the frame closer to the lights.
Also the reason you use a relay is so the high current for things like lights don't burn out the contact in the switch, unless you were to use a large switch of course.

As for adding a circuit for high beam you could simply use the existing relay with a line from the high beam but add a diode to both the activation lines to the relay to stop either circuit activating the existing lights.

tonylester thanks for the info.

I've modified my plans a bit (diag below). I'd like to wire the DRLs up so they come on automatically with high beam but are switchable with the dipped beam. At the same time include a fuse block to supply current on engine start.

The proposed wiring diagram (below) doesn't have a diode in feeds the from the lights to relay contacts 86, but should they?

I'm thinking .. why not just connect them via a switched ignition source? No need for the complication of high and low beams, two relays. DRLs are usually on all the time. Put an on/off switch in the line for operator over-ride.

I want to use the dipped/main beam feeds to trip the relays so the DRLs only come on with the main lights (and engine running). Lots of riders say the main light feeds, where their wires enter the light cluster, are one of the easiest places to locate and tap into. It's a bit cramped but, with the windscren removed, not difficult.

DRLs, as opposed to running lights and fog lights, are normally much brighter than other front-facing lights. I think it's unreasonable (and illegal) to use them with dipped beam after sunset. The ones I've bought are much, much brighter than dipped beam. So the idea of this circuit is to always have them come on with high beam to boost nightime light levels (and if you flash another road user ).

That's not going to work, unless you are flashing your main beam. The dipped beam goes out when you switch to full beam, so no power to your DRLs.

You want the lights to be on with high beam, and switchable with dipped.
So, go back to your first diagram, with a proper permanent earth or -ve connection for the lights.
Ditch the fuse between the relay and lights. keep the one between the relay and battery.
(fuses should always be as close to the power source as possible, and rated lower than the rating of the wiring used, rather than the device)
The feed for the relay goes to the high beam, thus making the DRLs come on when high beam is on.
To let you turn the lights on without high beam, fit a switch that bypasses the relay.
As mentioned above, these are LEDs, a reasonable quality switch can turn them on and off, no problem.

That switch will let you have the LEDs on anytime, handy for night time repairs and draining the battery.(depending on the power of these LEDS)

If you want to only have the DRLs on when the engine is running feed the switch from an ignition live source. If you can't find one that looks like it can handle the current, use a second relay in parallel with the other, with the switch feeding the relay from the side or tail light.

Okay. Then I'd call them spot-lights; DRLs being legal to have on at any time.
If my spots were LED I could imagine wanting the option to use them independently of the headlight. But they're halogen, too hungry when parked and too bright for on-coming traffic.

We're straying off-topic here so I started a new thread in the Tech forum for the 'when you can operate DRLs'. All I can say at the moment is it's bit confusing. http://www.horizonsunlimited.com/hub...527#post529613

Thanks for the info but I think the circuit as detailed is still going to deliver what I want...

Actually this isn't right - the dipped is on all the time (my bike's a 2008 twin BTW). This is why it's often recommended as an ignition live source, especially for power-hungry accessories.

The fuse block after the relay is for powering ignition live accessories (this includes the DRLs). If I put it between the relay and battery it would be live all the time (I already have a second fuse block for that). But I do see your point, that's why the v1 circuit also had a single fuse 'before' the relay, to protect it.

The final circuit is shown below. This provides on/off with dipped beam and uses the DRLs as auxiliary lights with high beam. The 1600LM Cree lights I fitted vastly improve near-medium distance illumination. The fuse blocks are interchangeable with single, in-line fuses if preferred.

If space is tight I'd advise getting micro-relay switches as they're a bit smaller.