Changed headlights, relay(s) required?

[striderider]

I've recently changed the single H4 headlight (dual filament with separate running light) to a dual bulb H7 setup (1x dipped, 1x main & separate running lights)

Before:



After:



I've the switch gear for all-off (which works), running lights only (which works). However on dipped beam both the H7's are on at half-lumination. Then when flicking to high-beam I'm then getting 1 H7 at full brightness rather than both at both at full brightness.

I know I need to add a relay (or two) with a direct feed from the battery, this is where I'm lost as I haven't a clue how to wire one (or two) up or what type to buy.

Any assistance hugely appreciated

[Buzzin (^_^)]

Ehm, since both lights seem to operate at once I suggest you sort that out first.
My knowledge of electricity isn't great, but even with a share Ground wire both lights shouldn't come on at the same time.
I think you might have connected a wrong wire somewhere...
See....if both lights are on, the H4 bulb would have had both lights on as well, and I assume it didn't do that. (it shouldn't unless you use the pass button)

So sort that out first, and then when it turns out the lights draw too much power you can start using relay switches. That would probably only be needed if you plan to ride with both lights on at the same time. If, like an H4 bulb you switch off the dipped light when using the main beam the switch should be able to handle the power (currently an H4 is probably 55/60 W and an H7 is pretty much the same)

[striderider]

Thanks Buzzin,

The standard OEM loom used a single H4:



I was (perhaps wrongly) advised that the H7's have a positive feed & an earth. So I wired it as per below: The plan was to have 1 H7 as dipped, then when on high-beam the other H7 is also turned on.



I have since been told the earth is not to the original light loom, but direct onto the frame - this I tried & had no dipped at all & main was only on one.

Scouring the different bike & car forums up and down the net has suggested I wire up as below:



Within the 2nd pic it does seem as though they are in Series on dipped. If I remove the ground from the High - where else would I ground it?

[Buzzin (^_^)]

You might want to add a diode to both ground wires to stop the current from one light flowing to the other....that should solve part of the problem.
I'm not electrician, but I don't see why your setup wouldn't work (with the diodes in place)

[jup]

I'm with Buzzin. Don't see why it wouldn't work with some diodes. However, do know it's all voodoo, electricity.
You need to make sure that all the amps, volts, ohms and watts equal in the great complex math they are involved in. Or they will either draw too much, not enough or have too much resistance for the power supplied to power both bulbs when wanted.
I need to have a sit down now. Brain overheated.....

[striderider]

I've found part of the problem.

The ground on the original H4 connector was on the wrong place - so both the H4 bulbs were in parallel. (hence only receiving half the volts normally)

I now have full illumination on each individual bulbs (one for dipped & one for main/full).

The third diagram I hope is the setup to have both bulbs at full illumination when on main/full beam.

[Buzzin (^_^)]

Ah yes... if you want both lights to come on when selecting full beam I think a relay might be in order, this partially because the load on the switch would be to high, and partially because the current setup won't support it.

But, you might want to look into changing the actual switch on the handlebars. It quite simply doesn't connect both wires at the same time....if you change it, it might do that. Make sure you test this properly for heat before finishing.
Both the switch and the wiring might get hot....if they do, change it back and build it with a relay....

Personally I wouldn't bother...the light of the full beam should be enough in most cases...


(and that is probably as far as my electrical knowledge goes ...)

[striderider]

I've still some (always-on) LED running lights to add - best to be seen eh?