[Bach415]

Originally Posted by EndlessAzure

Not quite. The HiBeam flap is actually always actuated when the DRL is on using the "Resistor Tap" method. I verified by shining a flashlight into the projector while a friend toggled the parking brake. The flap moves as the DRL LED Bar is turning on and off in Option 0 (Day Mode) in unison with the parking brake.

In "Resistor Tap" method, the LED Bar is also running in DRL mode at full brightness in Option 1 (Parking Mode). --> Same HiBeam Flap issue occurs (verified by toggling e-brake), which is why it is especially apparent when you toggle from Option 1 to Option 2. The light turns on faster than the DRL Resistor relay can turn off the flap, which is why the HiBeam blips.

Edit:I just thought about it and there isn't a flap on the base headlights. Also if the headlight flap is actuating even just from the e-Brake toggle, then it's most likely what you had a theory about. Untapping the live wire from parking 12V might not even make a difference. That also means that the DRL resistor makes no difference in terms of the flap. Only for the brightness.

Originally Posted by EndlessAzure

I want to state that it is generally agreed that the resistor must be uninstalled to avoid toggling HiBeam flap during Option 0. I think this is still accurate, so I will proceed without completing the circuit through resistor ground.

Summary of FRS Base-model power modes:

• Option 0: (Day): Parking Power (De-energized)
• Option 0/1 (Day/Parking): HiBeam Power (Always Energized) | LowBeam Power (De-energized) | DRL Relay (series with Resistor) | HiBeam Function (Switch DRL Relay to resistor bypass, Momentary Energize LowBeam)
• Option 1/2 (Parking/Night): Parking Power (Energized)
• Option 2 (Night): HiBeam Power (De-energized) | LowBeam Power (Always Energized) | DRL Relay (Always resistor bypass) | HiBeam Function (Momentary Energize HiBeam)

I don't believe Parking Power is causing the issue, but I will probe the car as you have suggested when I have a chance to get under it next.

Note that USDM headlights (Halogen and Monogram/RS/10S) do not even utilize Parking power. It goes to an empty pin and the circuit is never completed. (This is assuming that it isn't switched/relayed upstream). I have plugged the LED Bar into Parking Power (with no resistor), and the HiBeam flap issue does not occur. Furthermore, I would presume, unless the LED LOW and LED HIGH circuits are fully isolated and relayed internally in the JDM/EURO headlights, that the HiBeam Flap issue might occur as well on FRS Base models.

I think the car still uses HiBeam to power the DRL circuit in Option 1, providing dimmed halogen DRL on the stock lights. Whenever you pull on the light stalk for actual HiBeam for Option 0 or 1, the car simply flips the DRL relay to bypass the resistor. If you look in the engine fusebox and pull the DRL relay, you'll notice it's a 5-pin Changeover Relay.

Edit: Based off of your previous statement from above, it makes removing the DRL resistor kind of useless if you are still tapping the DRL live wire unless you just want the full 12V power and not care about the temporary flash of the high beams. Regardless of removing it or not, the flap is still being actuated if the circuit is still being completed. It's like on the base headlights, if you remove the DRL resistor by default, it shuts off the DRL. If you remove the DRL resistor but extend the wire to something else and complete the circuit, you'll most likely have the full power high beams instead of a low power high beam as DRLs. The only way it's important for removing the DRL resistor is if you are tapping a 12V for the DRL LED strip from another source that isn't the high beam.


Even though the parking 12V is not utilized in stock applications, some people utilizes it to do the always on mod as that provides power when in parking and low beam mode when the DRL is turned off. That's how I have my BRZs and JDMs set to so the boomerang/strip turns on when in parking mode/low beam mode only. No running DRL.

Originally Posted by EndlessAzure

Yes this is what I'm leaning toward. Unfortunately, as you have noticed, it may be a functional difference in power relaying between the base and Monogram models. As a work-around, I'm thinking of jumping the HiBeam power with a diode upstream of the headlight and not tapping into the Resistor (I have an always-on module I would like to include, which necessitates the diode). This would mean the HiBeam Circuit wouldn't be completed with LED Bar. Also implies that LED Bar will come on when I toggle the HiBeam on any mode

If you can find another 12V that is only on when the car is on and tap it there w/ a diode, then you will constantly have the LED strip on at full brightness without the possibility of running into the flap issue again (rather than still tapping the hibeam wire of the headlight). I know that the factory optional connector in the cabin has a 12V that is always on when the car is on. Maybe see trace that wire and see if it goes back to the engine bay and tap that one?