Headlight Relays

[smegballs]

Do modern bikes come with headlight relays as standard these days, or does the switchgear still take all the headlight current as is/was done traditionally?

Also headlight relay general, has anyone done it themselves? Was there a noticeable difference in the light output? Considering doing it to my sisters ZZR as the lights are a bit pants.

Supposedly this is what it can do.... (on a car)

https://i.imgur.com/nIK2AId.jpg

Shame they didnt keep the camera at the same focal point down the road to do an accurate side by side comparison....


For anyone wondering what a "headlight relay" is, I'm talking about the practice of using heavy cable and a relay to drive the headlights straight from a (fused) battery connection in order to minimise voltage drop. The switchgear connections then only handle the small currents needed to active the relay coil, as opposed to handling the full ampage for the headlights.

Supposedly just voltage drop of a volt or two (easily done with old corroded switchgear contacts, and thin stock wiring harness) is enough to drop the output of headlight by a large amount (>20%)

[barrkel]

I know my 2005 VFR uses relays, one for the two dipped bulbs, and another for the two full beam bulbs. And a third relay for the starter switch, to turn off the headlights at ignition time.

I know this because my headlights have stopped working, but the fuse and bulbs are OK; mechanic believes it's corrosion in the starter switchegear, which I have yet to check for.
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Bikes: S1000R, SH350; Exes: Vity 125, PS125, YBR125, ER6f, VFR800, Brutale 920, CB600F, SH300x4
Best road ever ridden: www.youtube.com/watch?v=s2MhNxUEYtQ

[stu_m]

the first place to start would be at the bulb connectors

compare the voltage there with what you have at the battery if there isn't a lot of drop then you may just be wasting your time!

I have a suzuki TL1000s and the wiring is rubbish on them and these benefit from relays, I have heard of voltage been as low as 10v at the bulb connectors!

Mine are a massive difference now they are on relays

[J.M.]

Have you measured the voltage to see what it's actually like at the connector block? If you've got corroded terminals, I'd personally be sorting those out instead of wiring in a relay and a direct battery connection.
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2004 R1 & 2018 XSR900