Daytime Running Lights

[S_J_P]

I've seen a lot of cars whose daytime running lights remain illuminated at night (along with their headlights), but the Aygo's extinguish as soon as the side/headlights are turned on.

Does anyone know whether it's legal to have both the running lights and the side/headlights on together (I presume it is as other makes do it, but I wonder whether the low placement of the Aygo's makes it a different matter)

Secondly does anyone have an idea how the interlock operates? How does the side/headlight hold-off the running lights, and how can this be defeated?

I'd initially assumed it was relay controlled, but the set/disable process for the running lights (ignition on, cycle lights three times) makes me wonder whether the ECU has a hand in the control?

[Spazmoid]

Yes completely legal as long as they are dimmed when the side are illuminated.

If I understand your question on how they work on the Aygo; when the DRL circuit receives an on signal from the side light circuit they switch off the DRL circuit. A simple relay will handle this and should be very easy to change for the price of another realy from Halfords. I doubt that the ECU is used to control the light state conditions when a relay is a far cheaper option - perhaps someone with a FIRE can comment on the wiring further.

I've installed the Philips DayLight 8 DRL 12 V 6 W LED solutions (12824WLEDX1) on my 2012 Aygo Ice and instead of having them dim on the side light circuit I connected them to the main lamp circuit so they dim on dipped & main beam. This is against the law in this country but legal in Sweden and other countries.

Horses for courses really.

[S_J_P]

So a relay swap should do the trick, and allow the driving lights to remain operational (albeit dimmed) when the main lights are turned on?

I didn't think you could dim LED's, so I presume you can't just fit a relay which switches between dimmed/undimmed and that there must be some sort of control circuit which controls the driving lights? Is it possible the Aygo Fire driving lights extinguish when the main lights are turned on because they don't have a dimmer circuit?

[Spazmoid]

Yes LED's can and do dim - not sure how my Philips do that without taking them apart but I'm sure they use a twin voltage LED bulb. As for the DRL's on the Fire you would need to let me know how they're wired; I am guessing here that the connection between DRL and main lamp circuit is made to the right of the steering wheel (RHD) where the ECU and lighting relays are located.

If you're able to see with the bonnet up tell me what wires connect the DRL's. You will have a main solid color wire and then another wire with a main color and a trace color as well.

[S_J_P]

The DRL's are ensconced within the bowels of the front valence, I can just about see the osf cabling but only the outer corrugated sheath which appears to enter the main lighting loom behind the headlight, so I can't advise the colours.

What confuses me a little is the way the lamps operate, they don't come on when the ignition is on, they wait until the engine has actually started. When they extinguish, I can't hear a separate relay operate, neither can I find an extra relay for them (I have come across the front fog lamp relay located behind the radio) but that's probably because I'm looking in the wrong place! The Haynes manual I have is for the pre-facelift model and if of limited use now.

I think that in light of the legislation and the comments I've read about the lamps, I'll leave them alone and only have them on (at full brightness) during daylight!

The Parrot bluetooth kit and Scangauge I've installed can be the token extras which should placate my desire to tinker,

[Jan van de Wouw]

Dimming of LEDs is usually done by altering their dutycycle, so they're off for part

of the time, but the on/of switching is so fast you don;t see them flickering...

As for the relay; the're probably driven by transistors: those don't click but are solid state...