Member Since: 08 Mar 2010
Location: Warwickshire
Posts: 1477
LED Sidelights as DRLs 2009-2013 D4
So this question has been asked many times: you have a 2009 -2013 D4 with xenon headlamps and LED signature lights. You want to use the LED signature sidelights as DRLs. Well of course the LED signature sidelights are nowhere near bright enough to be like the LED DRLs that you will see on many new cars, after all they are sidelights – that is what they were designed to be. As we all know the DRL settings in the CCF file do not help because all this does is turn on the dipped beam headlamps permanently (in one of two different modes, Scandinavian or Canadian).
Whilst many will have differing opinions, there is a desire from some forum members to be able to drive around with the LED signature sidelights on all the time so that they look a bit like LED DRLs, even though clearly they are not. Many won’t get this desire and will think that it is an idiotic idea; I do get it and I’m going to do it.
Achieving this presents a few issues which I discuss below:
1) You could just turn the sidelights on every time you get in and turn them off when you get out. Three problems here, it renders the auto headlights useless because the switch won’t be in the auto position, you have to remember to do it which is a pain and the rear (tail) lights will be illuminated (so it will look like you are driving with sidelights on – which of course you are, rather than DRLs) along with the instrument lighting.
2) There has been talk of simply finding an ignition switched live and simply splicing it into the wire that feeds the DRLs at the back of the headlamp plug. Again two issues here, the rear lights on each side respectively are powered from the same circuit as the fronts on the same side so will also illuminate permanently as well (confirmed from wiring diagram) and who knows what else might be made live and cause all sorts of issues if you apply a live to that circuit when it’s not supposed to be live (when the light switch is in the off position for example).
3) Alternatively you could cut the LED feed wire from the back of the headlamp (rather than splice into it) and connect the ignition switched live directly to the LEDs through the multiplug. This works perfectly in all scenarios other than when you come to park and need to leave the sidelights on. What will happen in that situation is that you will have no front sidelights when ignition off and headlight switch in sidelight position because the LEDs are only being fed by an ignition switched live.
So to do it is clearly going to involve a bit more work. To recap what I am trying to achieve is the following:
1) Headlamp switch in position 0 (off) and ignition on = front LEDs only will be illuminated
2) Headlamp switch in position 1 (sidelights) and ignition on = front LEDs and rear tail lights illuminated
3) Headlamp switch in position 2 (headlights) and ignition on = front LEDs, headlights and rear tail lights illuminated
4) Headlamp switch in position 3 (auto) and ignition on = as per (1) if light sensor detects its light and as per (3) if light sensor detects its dark
5) Headlamp switch position 1 (sidelights) and ignition off = as per (2)
It’s worth noting at this point that I am not an auto electrician or any other sort of electrician for that matter and only have access to basic DIY tools and equipment so the solution may well end up looking a little amateurish. Please don’t harass me for that, I’m doing it because I don’t like being defeated by the machine; I may not even like the end result and end up reversing it again (if I do that the only evidence that it was ever done should be a single in-line connector in the feed wire to the LEDs at the headlamp multiplug).
So excuse (again) the amateurish diagram below; this is how I think the wiring needs to look. The purpose of diodes 1 and 3 is to ensure that when an ignition switched live is applied to the sidelight circuit nothing else on that circuit becomes live (e.g. rear tail lights or anything else that I don’t know about). The purpose of diodes 2 and 4 is firstly to ensure that when the sidelights are on and the ignition is off we don’t make live the circuit (and anything else connected to it) where I pick up the ignition switched live from and secondly that I preserve the concept of separate fuses and circuits for left hand and right hand side/tail lamps when activated by the headlamp switch. This concept does mean that when the ignition is on and the headlight switch is on (either manually or on auto) the LEDs in each headlamp will actually be fed by two live feeds. I don’t think that is a problem as the diodes will ensure nothing becomes live that shouldn’t in other scenarios.
This of course does involve cutting the sidelight feed wire at the back of the headlamp. That does make me slightly nervous but hey ho.
Anyone else that wants to try this does so of course at their own risk. This post implies no level of assurance that you won’t cause damage to your vehicle if you fancy trying it. I’ll be doing one headlight at a time so hopefully if things go wrong the damage potentially will only be to one side, unless the whole thing goes up in flames!
Finally I intend to use the (unused) air pollution sensor wires behind the grille for my ignition switched live.
One of the things I will need to test is that I haven’t upset any of the towing electrics. I don’t see why it should but you never know.
So here is the diagram:
And here are the diodes laid out with the wires and connectors
Click image to enlarge
Here the connectors are crimped and heat partially heat shrunk:
Click image to enlarge
Here are the final made up mini looms with the diodes and all connectors in place:
Click image to enlarge
So in the last picture the red connectors with no wires in them will end up connected to the car's loom where I cut it at the back of the headlamp, the blue connectors with two wires on one end will be connected to the sidelight wire at the back of the multi plug and the ends of the coiled cables will be connected to the pollution sensor ignition switched live.
I'm about to decamp to the garage (SWMBO is away) and get the wire cutters out behind the headlamp. Wish me luck
Last edited by discoteca on 3rd Dec 2014 10:41 pm. Edited 1 time in total
3rd Dec 2014 8:09 pm
discoteca
Member Since: 08 Mar 2010
Location: Warwickshire
Posts: 1477
Grrrrr too much time browsing and replying to other posts than cutting and joining wires tonight, I'm going to be here all night . Can't you just tell SWMBO is away (I've been waiting to fit these D4 LED indicator bulbs since Monday as well )
3rd Dec 2014 9:38 pm
discoteca
Member Since: 08 Mar 2010
Location: Warwickshire
Posts: 1477
Good news. All done. No blown fuses, no electrical fires (!) and no fault codes. Took a couple of hours (already had the basic components built up and had done a lot of planning prep) and everything worked as expected first time round. Very pleased with the result.
I officially name this mod as the D4 DRL mod (Discoteca's Running Lights) 8)
Last edited by discoteca on 4th Dec 2014 1:45 pm. Edited 1 time in total
4th Dec 2014 1:39 pm
DSL Keeper of the wheelie bin
Member Since: 11 May 2006
Location: Off again! :-)
Posts: 72787
Or D4 DiscoLights.
4th Dec 2014 1:45 pm
Parallax33
Member Since: 03 Jun 2014
Location: Christchurch
Posts: 1125
Member Since: 12 Aug 2014
Location: Southampton
Posts: 1809
Nice work - what we've all been waiting for! Reckon we should get the Southampton D4's updated don't you think Justin? Stolen - D4 Loire Blue
D4 Bali Blue
4th Dec 2014 3:37 pm
Parallax33
Member Since: 03 Jun 2014
Location: Christchurch
Posts: 1125
Sounds like a project we need to do together Nick! Justin
Member Since: 07 Oct 2014
Location: South
Posts: 121
Personally, I'm ok with the tail lights being on (as DRLs) as literally most premium mark manufacturers do this (BMW, Jag, Audi).
If we want that, it makes our lives a lot easier
4th Dec 2014 5:48 pm
discoteca
Member Since: 08 Mar 2010
Location: Warwickshire
Posts: 1477
Lucero, I don't agree - most new cars including premium ones do not light the tail lights in daylight when the front DRLs are illuminated. To do it with the tail lights on, the way I see it, you still need one diode per side to be electrically 'safe'.
4th Dec 2014 5:53 pm
Lucero
Member Since: 07 Oct 2014
Location: South
Posts: 121
Still can't agree, sorry. It just looks wrong. My BMW has DRLs and all lights (side lights) are on. Interestingly, that's only a halogen bulb upfront and probably not as bright as the disco 4 led side lights. I'm currently sat in a 14plate A5 which also has DRLs and these are also all on.
You mentioned that there are two settings for the Disc scandanavian and Canada. If you toggle those options, Canadian puts just the front lights on and Scandinavian does all lights.
4th Dec 2014 6:52 pm
Parallax33
Member Since: 03 Jun 2014
Location: Christchurch
Posts: 1125
So Lucero, how are you suggesting you would approach this little conundrum? Im interested in your ideas because we haven't made the "Cut of no return" yet Justin
Member Since: 12 Aug 2014
Location: Southampton
Posts: 1809
Scandinavian & Canadian
From views on this forum I had it that
Scandinavian operate lights on all the time when engine running.
Canadian mode operate when drive or reverse is selected and park brake released.
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
. Can't you just tell SWMBO is away (I've been waiting to fit these D4 LED indicator bulbs since Monday as well 
)
. Back to the D4 DiscoLights solution 
