How to turn BRZ Headlight LED into DRL
 

Hey guys, first off I wanted to say thanks to everyone who makes this forum possible. This community is by far the best I've ever belonged to. That being said I felt I should contribute. I have extensive electrical knowledge so what better thing to modify than our headlights. I personally feel Subaru fell short in this department, the LED horse shoe is already there so why not take advantage of it! First things first this mod isn't hard but should only be done if you're confident. Secondly, I will not take responsibility if you burn down your car, house, or neighborhood (very unlikely). Third, I'm more than willing to help out with any questions so feel free to send me a PM.

Parts/tool list
solder and iron
socket wrench and 10mm socket
screw drivers
multimeter
wire strippers
electrical tape/heat shrink
18-12 gauge wire
diodes which I picked up at my local radio shack. http://www.radioshack.com/product/in...ductId=2062591
These diodes are rated at 6 amps and 50 volts and will do just fine.


There are many ways you can accomplish this mod but I like things to be simple, clean, and easy. This walk through will show you how to do exactly that. I would suggest removing the negative from your battery but its not completely necessary. I like to check all circuits with a multimeter while working which cant be done without a battery. I know the correct wire colors for a 2013 so if you want to disconnect the battery than be safe, not sorry.

I wanted my head light LEDs to be on when the lower DRLs are on. Because of this I grabbed my power from the DRL circuit. I know some of you may want the LEDs to be on under different circumstance so this will be the variable. Accessing the DRLs can be done from many places however I chose to get it from the DRL itself because it was quick and easy. Pull your fender liners buy removing the FOUR plastic clips securing it to the fender.

Attachment 59487

Once the liner is out of the way you can remove the two 10mm nuts to allow the DRL to be removed from the front.

Attachment 59488

The 12 volt supply wire for MY 2013 BRZ is the white wire. I always solder and tape my wires, this ensure the connection will not fail due to vibrations (this is a car after all). Once you're done attaching a two foot 18-12 gauge wire to your DRL you can route the source wire up to your headlight.

Attachment 59489

Attachment 59490

I chose to make my attachment to the headlight side of this connection to keep it out of sight of Subaru service eyes. If it appears stock then most likely they will think its stock. I suggest you do the same however it can be difficult to access the wires (I have bigger hands so if I can accomplish this I'm sure many of you can as well). Remove the headlight connector and strip some of the heat shrink to reveal your headlight LED anode (positive). In my 2013 BRZ this wire is green.

Attachment 59491

I have read through a lot of posts about doing this mod and many of you have encountered a few issues. If you were to simply attach your 12 volt source wire to your green head light wire it turns on all the cars lights. There are many ways you can work around this but like I said, simple, clean, and easy. This is where your diodes will come into play. The image below will show you how to attach your diode into the green wire. you will have to cut this green wire and splice the diode into the circuit. The diode will allow current to travel from the lower DRL into your head lights LED anode powering the lights on at the same time. The diodes primary job is to stop the current from back feeding into your body harness eventually into some type of BCM which powers your running lights ect. Its very important that you splice the diode into the correct direction. Doing this wrong will cause the head light LEDs to not turn on at all. I highly suggest you solder the diode into place.Be aware that when soldering a diode you must "flash" solder. Transferring too much heat to the diode can damage it so wait till your iron is good and hot

when using a diode remember this, current will travel from black to silver but will not travel from silver to black. The diode below has a 6 amp threshold (more than enough for LEDs).

Attachment 59492

Once its all done it will hopefully look something like this.

Note that in this image it may look like my source wire is attached to the body harness side of the diode but I assure you its attached to the anode side of the diode

Attachment 59479

Once you're done secure your head light connection back to the head light and start on the other side! The picture below is the final product, looks stock to me!

Attachment 59482

Once the other side is done its time to sit back and enjoy the view!

Attachment 59480

I wanted to include a picture with the headlights fully turned on as well. This photo shows that when the head lights are turned on current travels through the diode and down to the lower DRL making them turn on. If this is what you desire (I did) then you're all done. If you want the lower DRLs to turn off once the head lights are on all you have to do (see picture below) is install another diode in your source wire(my red wire from the DRL). I'm sure a lot of you will have plenty of questions so please don't hesitate to ask. Congrats on a job done!

* follow this diagram if you wish for the DRLs to turn off when the HID headlights turn on (stock behavior). Thanks to @CIAGDDS for the great visual.
Attachment 59481

Excellent write-up, definitely going to do this once I get a full weekend and some time to myself.

nice job......just ebayed diodes! thanks for DIY.

Impressive. I was hoping someone would write a DIY on this for a very long time.

Sigh, I wish I had the electrical technician skills to do this, too scared of messing up since I've never soldered anything before :| looks like I'll have to take it to an auto shop and pay.

Also, do the DRL bars dim? I've heard that it might pose a blinding issue at night to other drivers.

..exactly which wire you must cut and re-wire with diode?

right electrical wiring? It's this way? your red wire goes to white 12+ DRL (soldered)?

^ This. The DRL, in my opinion are fairly bright when used alone (not bright enough to drive comfortably at night, but enough for you to see where you are going at low speeds). I thought I read somewhere that they were turned off by default when the headlights are on due to them being bright and not angled properly for night time driving. Then again, I could be completely wrong. I did get this info from the Internet after all :lol:

On topic, nice write up! :thumbup:

Good stuff, surprised it took this long for someone to write up a DIY! Thanks!

Well, Off to Radio Shack:)

Now can you figure out how to turn the front fog lights on without the main head lights?
(Using the turn stalk, when the ignition is on)
Thanks again for this DIY.

Don't Sweat it, if you take your time and follow the walk through you can do it. Dimming LEDs is possible but it requires the right components. When metering the DRL harness I got 14.5 volts. Its possible to lower the voltage via resistance and dim the LEDs but it depends on the factory Subaru LEDs. Someone should try it when doing this mod. I bet you can dim them slightly before they turn off all together. I doubt Subaru would use dimmable LEDs when they never intended to dim them.

you must cut the green wire located on your headlight harness.


that looks right, I assume the white mark is the silver side of the diode which is the side you want facing your headlight.

I wish I had fog lights to really dive into it. send me a pm and I can direct you in the right direction.

so if you want to NOT have the LEDs light up when the headlights turn on is this what you add to the added power wire?

http://i.imgur.com/8FBKgYU.jpg

On my FR-S, the LED DRLs dim when the headlights are turned on, so I agree, they would be too bright at night without dimming or turning off.

Thanks for you confirmation! that's right!

If you want to lower DRLs to turn off when the headlights are on than add a second diode to your source wire (white DRL wire) with the silver side of the diode attached to the headlight. This will allow current to travel from the DRL to head light but stop current from headlight to lower DRLs

Attachment 59557

^ I see, thanks.
had the diode the wrong way.

Subbed. I'll probably do this mod at some point once I get my BRZ back. Thanks for the awesome write up!

Sorry to clarrify
http://www.ft86club.com/forums/attac...2&d=1386567109
The red wire there is the wire from the DRL, the side that it is attached to, does that connect to the green wire from the head light harness , and the left side of the diode connect to the brown wire from the head light harness?

Sorry not really good with electrical stuff, really want to do this but a bit confused, if some one could do a basic ms paint of how to wire it up would be much appreciated.

You must cut green wire. The side with diode (_|) goes to green wire harness side.
The other side of cutted green wire must be wired to anode. From cathode (K) you reach white 12+ of DRL.

Alright I understand it now. Thanks for the clarification.

im seriously impressed you got that diode in there on the left side infront of the drivers seat.

there is almost no space there. i just added extensions to the green wire. even adding those extensions were a pain.

Thanks, I work on circuit boards all day so our engine bay is much larger than I'm used to. It did take me some time to be completely honest. How did your install go?

Like Trap said the diode gets placed into the green wire. The silver side of the diode facing your headlight while the black side facing your body harness. you have a 50/50 chance of getting it right so good luck! :thumbsup:

Cool. But can't ya just turn on the driving lights and have same effect? :P

I was going to ask this as well.

You could have just made it so the DRLs stayed on with the headlights without worrying about the boomerangs, correct? Or am I missing something?

Edit: I guess it seems to be the simplest way to get the DRLs to stay on with the headlights though.

I enclose my wiring for better understanding.

In my schema: cut the green wire
brown=====> to white DRL wire
yellow=====> soldered together brown *======>CATHODE side of diode
blue======> soldered to ANODE.

CATHODE TO GREEN WIRE OUT OF HARNESS
ANODE TO GREEN WIRE OF HARNESS.

http://img34.imageshack.us/img34/7010/39f8.JPG

Basically once you get the green also cutted, insert the diode in this way.
http://img853.imageshack.us/img853/1813/16fz.jpg

Another suggestion for front foglight.
Maybe possibile (with another diode) to have fog light ON when you have high headlights ON.......very JDM for aggressive highway trip.....all people grant you a bit of road here, but not so polite....

I HAVE JOINED THE CLUB!
i added an extra diode on the power wire to have the DRLs turn off when the headlights come on

http://i.imgur.com/4bgvxou.jpg
http://i.imgur.com/Lj9fmD4.jpg

headlights on
http://i.imgur.com/p1nnMmu.jpg

impressions of this DIY: Its easy on paper, but actually doing it is a huge pain in the ass. so little space to work with.
but when you finish it, it feels good :)

Wired according to this DIY, Thanks again OP:)
Made a small wiring "harness", made it a lot easier to maneuver with the solder iron.

This is sweet. Another thing to add to the summer mod list :sigh:

but honestly :thumbup:

Doing this will turn the boomerangs on indeed but it will also turn all of your night related driving lights on too. This will allow you to just leave the lights on auto.

good job, welcome to the club :party0030:

I have another problem with this. When I back the car out of the garage, I don't want to get back in the car :P Gotta stand and stare for awhile. Thanks again to Lithium and Trap63 :)

Just a reminder for those that remove their bumpers more often then others, might want to use quick disconnects. :D

Good point, using a connector on your "Source" wire (my DRL) would help out a lot if you have to remove your bumper cover.

Thank you so much for this writeup. Waited forever for someone to figure this out!

No problem, let us know if you have any trouble doing yours. There's at least four of us who can help.

May I ask a silly question? I do not understand the 'LED horse shoe' you referred to in the writeup. I played with my car for a while tonight and I cannot get it to light up. I am really confused. What is the function of this things and how can I turn this light on? Thanks a lot for the help.

If you turn your park lights on (one click up from auto) it will turn on the boomerang lights. these lights surround the HID projector in our headlights.
This DIY shows you how to turn the boomerang into a daytime running light.