Originally Posted by Sean

Sorry for bumping the old thread. I'm planning to change out my headlights this weekend (hopefully). I've read through most of the threads discussing headlights, which can obviously be confusing especially the older ones. I just want to clarify a couple things I'm still not sure about.

1. Using the relay as detailed in the OP, does that make the LED on all of the time when the car is on? Even when in auto mode during daylight? This is my understanding if the LED is wired to IGN2, however some posts seem to indicate otherwise.
2. Is it better to use IGN2 or the fuel pump resistor to power the LED? I see mentions of both ways but don't understand the pros/cons.

Originally Posted by Sean

Sorry for bumping the old thread. I'm planning to change out my headlights this weekend (hopefully). I've read through most of the threads discussing headlights, which can obviously be confusing especially the older ones. I just want to clarify a couple things I'm still not sure about.

1. Using the relay as detailed in the OP, does that make the LED on all of the time when the car is on? Even when in auto mode during daylight? This is my understanding if the LED is wired to IGN2, however some posts seem to indicate otherwise.
2. Is it better to use IGN2 or the fuel pump resistor to power the LED? I see mentions of both ways but don't understand the pros/cons.

Originally Posted by 737NG

Yes the LED'S will be on all the time, Even in the auto mode. I always keep my switch in auto. when the lights come on the LED'S will dim to 50%. When the lights go off the LED'S go back to 100%.

As far as what fuse you wire the LED'S to, It's up to you, there isn't any pro's or con's.

Originally Posted by harper7

Just did mine a couple of weeks ago. I used a Bussman add-a-circuit mini fuse tap off the IG2 to power them 100% any time the ignition is on.Then I used another add-a circuit fuse tap off the headlight fuse which only get power when the headlights are on to trigger the relay to the 50% power when they are on., The headlight fuses are in the same row as the IG2,and are the forward two 15 amp fuses marked H-LP R LWR and H-LP L LWR and that's the one I used to tap off of as it fit good next to the other tap. Works like a champ.
Attachment 353298

Hi, i just wonder did you add the five way terminals relay? Or you just used two add a circuit mini fuse things?, if that it will be a simple hook up thanks

Originally Posted by 737NG

I have figured out a low cost solution for automatically switching the 100% brightness to the 50% on the 2011/2012 headlights for the 06-10 models that have upgraded their headlights.

First we will start with a very common relay (R51) used on thousands of applications.
this relay is a 5 pin relay availible just about at any automotive retailer. The average cost of this relay is around $8.00. Tools needed for this project are very basic.

1. Wire strippers/cutters
2. Terminal crimpers
3. 16-18 ga. wire
4. blade terminals.
5 Heat shrink or electrical tape (I prefer heat shrink)

Pin 30 and pin 87a are normally closed (allowing power to flow through the relay to the 100% brightness. The relay is de-energized at this stage. Once power is applied to the coil (pin86) it will move the contact to pin 87, therfore opening the circuit to the 100% and supplying power to the 50% brightness.

You will have a wire coming from the IGN2 fuse to Pin 30.
You will have a wire coming from pin 87a to the 100% wire (green)
The 50% wire (black) will go to pin 87.
Pin 85 will go to ground.
Pin 86 will be power to energize the coil to actuate the switch. You will use power from the parking lamps to pin 86.
Most all relay have the diagram on the side .Follow the diagram on the relay but all should be very similar.
Do this mod at your own risk. Neither I nor Club Lexus will be responsible for any damages.
I hope this helps all you fellow Lexus owners.