BRZ Headlight Running Light (the Boomerang) Schematic
 

EDIT: I have created a DIY for this. You can find it here.

I'm in the process of completely revamping my headlights with Luxeon Rebel turn signals, significantly brightening the boomerangs up, doing a lens swap, and washer modding the projectors. I created a schematic for the boomerang and wanted to share it with the forums.

Some readings I took tonight:

At 12.7v source voltage, the circuit pulls 154mA through each LED. The equivalent resistance of the parallel resistor circuit is 39 ohms. The dual capacitors in parallel with the Zener diode in reverse bias function as a pseudo-voltage regulator. The makes the boomerangs much less susceptible to dimming from voltage drops related to drops in engine idle rpm. The DRLs are really bad about this because there is no control circuitry or capacitor/Zener diode circuit on them. If you ever park your BRZ close to and facing a wall, keep your foot on the brake while slowly letting the clutch out, just enough to drop the engine rpm slightly, you'll see the DRLs dim, or even turn off. The boomerangs won't do this because of this circuit.

Information concerning the LEDs; they are Luxeon Rebel LEDs, just like the DRLs. They are considerably under-driven to eliminate the need for thermal management. Typically, these LEDs are designed to run at between 700-1000mA current, but those levels of current require considerable heat dissipation via the use of passive or active heat sinking.

Any questions, feel free to ask.

http://i.imgur.com/j3yBife.jpg

I have no clue what that sheet says, but if you can make a plug and play, or at least a starter kit for something like this, take my money now.

Subb'd, and very interested..

What kind of a kit are you looking for? Running the boomerang brighter like I'm doing? That would require disassembly of your headlight. I could offer a plug and play kit, you'd have to take the headlights apart anyways.

what all would a plug and play kit include?

Yea making the boomerang lights brighter, I am planning on baking my lights this weekend so it will be disassembled..

That will be awesome if its plug and play!! Want to see how it turns out first though, when are you planning on doing this?

I remember someone taking apart the headlight and seeing that there was only one LED to provide light for the boomerang. It may be possible to add more LED's to provide additional light. I agree that its too bad it isn't brighter in the first place.

I can assure you it's two LEDs, one on each end.

I can make it plug and play but you would have to ship me both parking light assemblies as pictured above this post. Turn around time would be 24 hours.

I now <3 Electric Engineers.


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Do you know why Subaru choose to not make them DRLs in the first place?


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I can't really answer that one. The actual DRL's are pretty damn bright already and it would cost more in parts to make the boomerang as bright as them. My guess is it was a cost saving measure in the same way they didn't put any voltage or current regulating circuitry on the DRLs.

Whew, I thought I was going crazy.

I'm stupid and tried making the boomerang brighter by simply bypassing the circuit board they're on and applying 12v directly to them. I for some dumb reason assumed they had regulators built in and dropped to the ~5v they need at the actual LED itself.. Result? Blown LED of course.

I had to go buy a new SMD, and flash-solder it to the circuit board. That was my first and hopefully last time doing that.

Could you repair what I borked, and make them brighter? I can pull and bake apart the lights this weekend. :)

Sub'd. Thanks for taking the time to do this.