Converting side markers into turn signals
 

The USDM BRZ/FRS side markers turn on when the headlights turn on. On the EDM/JDM spec BRZ/FRS, the side markers are actually turn signal lights. In other words, when you use your blinkers, the side markers will blink.

Does anyone know how to modify the USDM spec to mimic the EDM/JDM spec? Is it an entirely different wiring harness?

I'm not sure about the wiring harnesses differences between USDM and JDM, but if you're comfortable with splicing factory wiring this could be done fairly simply with about $10 in parts from RadioShack. Below is ONE method, I'm sure people will come up with various others.

1) Cut the pos/neg wires close to the side marker.
2) Crimp and heatshrink on insulated quick disconnects on the cut wires so they can be re-installed plug&play later, if desired.
3) Run appropriate length wire from front headlight blinker to side marker. Connect to side marker using insulated quick disconnect.
4) Vampire tap the extended wire from the side marker to the pos/neg going to the front blinker.
5) Wrap and secure the old constant power wires that used to go to the side marker.

This will change the resistance on the circuit and most likely cause your turn signals to blink rapidly. Mine already do anyway since I switched to all LED bulbs; I like the faster blink rate.

I know this seems pretty simple, but if there's enough interest I'd be willing to do it on my car, take some pictures throughout the process, and throw up a more well-written how-to.

excellent how-to. i suppose if i want to keep the factory blink rate, would it make this mod more complicated?

i wonder how the jdm side marker harness is wired with the blinkers.

My guess is that the JDM side marker is wired into the fuse box on a circuit that gets power only when the appropriate signal is turned on. Our side markers are probably wired into the fuse box on a circuit that has power when the headlights are turned on. I'd have to whip out ye-olde voltmeter to try to see if I could figure out how to appropriately rewire it there in the power distribution center (PDC).

This method of wiring - if both correct and possible - would keep the factory blink rate as well.

Someone please correct me if anyhting I say is completely inaccurate - this is all brainstorming, too late and too dark for me to actually look at the car while thinking.

when you do figure it out, please let us know. :bow:

i have the jdm clears right now and it looks a little too orange when they're lit. now i know why they made them amber instead of clear for the usdm models. :thumbdown:

I have the JDM clears also and put amber LEDs inside there. Mine also look a little orange-y, but the clear just goes so much better with my white BRZ.

I'm currently away from home but should be home Sunday. I'll try to start poking around then if someone doesn't beat me to it later today after wake-up time.

from a assembly line perspective, it would make sense to have a separate jdm and usdm circuits.

that way, the assemblers can plug all the harnesses together the same way no matter which model they're working on.

i have no background an electrical work and am purely guessing.

yup, i have the same amber bulbs as well. just a little too orange.

i can also confirm that the jdm spec uses the side markers as blinkers. it wasn't hard to confirm that the jdm brz side markers didn't turn on when the headlights were on since there are a ton of pics online with people's jdm brz. the hard part was finding proof that the side markers turned on when the blinker/hazards were turned on.

the video below proves this.

skip to 2:40 and pay attention to the side markers. you will see them blink.

[ame="http://www.youtube.com/watch?v=eP3SR1m_aRY"][SUBARU] SUBARU BRZ Movie - YouTube[/ame]

Since the front blinker is a dual filament bulb, there are a couple of ways to wire it as well. 1) do you want the side markers to be off and only turn on when you signal? or 2) do you want the side markers on with parking lights and blink as well?

if you want #1 then just tap into the parking light turn signal wire and ground like normal

but if you want #2, to be on with parking lights and blink as well, then instead of using the stock ground wire you need to tap it into the parking light wire and turn signal wire and leave the ground wire untouched. What this does is, the side marker when powered on, it uses the non blinking parking light wire as a power source and the blinker wire as a kind of a temporary ground so the side marker is on like normal, then when you hit the flasher it basically kills the ground and turns the side markers off so it blinks. When the parking lights are off it will basically do the opposite where it uses the parking light wire as a ground and the power comes from the blinker so the light will still flash with the normal blinker even with parking lights turned off.

I know its kind of a lot but thats electricity for ya, done this many times in different later gen hondas while adding jdm side markers

i would most likely go with mod #1. i think the amber bulbs are too orange to be constantly lit.

with mod #1, the blink rate will most likely speed up as mentioned before. i would prefer to stick with the factory blink rate.

i'll wait and see if there are other ideas to keep this mod as factory as possible. :thumbup:

Interesting... I would like #2 but my question is can we put clear LEDs which are amber when they turn on in there & have it blink at stock rate in synch with the stock turn signal lights?

ty

with the #1 method you will actually not cause it to hyper blink, systems are setup so if there is not enough resistance in a circuit (ie. dead light bulb) it will hyper blink, however if there is more resistance (with the added wiring) it will not hyper blink because there is still greater resistance in the circuit, hence the reason people have resistor kits for LED bulbs.
@Heero if you want the LED's only in the sides then it won't hyper blink but if you replace the turn signal bulb it will hyper blink, you can either cut the stock harness and add an inline resistor or just replace the relay under the steering wheel area with the LED one, check this thread out, they have some info on it http://www.ft86club.com/forums/showthread.php?t=11444

Don't Resistor kits have Resistors in them??

Yes they do, to kind of clarify what I mean I mean that when you buy led turn signal bulbs they can come with resistor kits because the LEDs do not create enough circuit resistance to prevent them from hyper blinking, but if you add resistance to a turn signal line by splicing in another bulb it will not cause the light to hyperblink