I'm only a very occasional visitor here but I'd like to share something - I did look through the threads for the 4th Gen ES300/330 and didn't see what I'm posting so hopefully I'm not duplicating the subject.
I wanted to switch my 2005 ES330's headlights to LED's and bought a high / low beam set which said 'Canbus compatible', and '99% of cars work fine with these bulbs'. Well my car didn't; the low and high beams worked fine but the DRL's didn't. In low outdoor light I could seem them dimly blinking occasionally. So, I snagged one of these canbus adapter sets that supposedly fixes the problem. When I installed the first one, on the passenger side, the driver's side lit up full brightness. Installed the driver's side adapter and neither light would come on (except in high beam, which still worked). I switch the adapters side to side, installed just one and then just the other, it was apparent that I didn't have a defective canbus adapter... they just didn't work with my car.
After doing some online searching I found the solution. And I want to begin by saying I do not own this company, I do not work for them, I do not know anyone associated with them, I am just a customer... a satisfied customer.
This company sells a setup which resolves the problem. Not only does it work, but when I emailed with a question they got back to me immediately; I placed an order and it went out the same day and arrived in two days - and for $15.99 and free shipping, which is cheaper than a lot of those 'canbus adapters' that did not work for me.
Here is their website: https://store.ijdmtoy.com/
Here is the page with the LED high beams / DRL fix: https://store.ijdmtoy.com/products/l...29241153552487
They have numerous variations, this is not a 'one size fixes all' deal. They listed my 2005 ES330 and I thought I'd give them a try. It's a little more involved than just plugging something in between the car's wiring harness and the LED bulbs but it's really not difficult at all. There is a harness that goes between the headlights; I took off the filler cover between the radiator and front bumper area and routed the harness cable through there. But I'll get back to that. Here's how it installs:

1. On the driver's side you unplug the high beam / DRL and plug the supplied resistor adapter onto the car's wiring plug. For the moment you leave the bulb disconnected.
2. On the passenger side you unplug the high beam / DRL. You plug one of the harness plugs onto the car's wiring plug, and one of the other two onto the bulb. There is a 3rd connector on that end of the harness which is not used on the ES330.
3. Route the harness across the front of the car and plug the connector on the far end of the harness, onto the driver's side high beam / DRL.
4. That's it! I did use tie wraps to tuck the wiring neatly away and keep it from chafing on anything sharp.
5. This is their webpage with instructions: https://store.ijdmtoy.com/pages/lexu...de-and-diagram

I started the car in daylight with the headlights set on 'auto'. The DRL's were lit, definitely so but nowhere near high beam level. Switched the headlights on and the low beams went on and the DRL's turned off. Flipped the headlights to high beam, and I had high beams! It all works the way it should. Not only is this a perfect solution to the LED headlight conversion problem with the DRL's on my Lexus (and many others, they have a compatibility listing for which one works with which cars) but it's insanely cheap for what you get - a wiring harness with 4 connectors, a mini-harness with a resistor and a plug, it actually WORKS, and it's all of $16 including free shipping. (Some places may have to pay sales tax in addition; I didn't.) I'd have been willing to pay 3x that much if I had to. You don't get a bargain very often these days but my hat is off to this company. They hit it out of the ballpark as far as I'm concerned.

 

A quick note to say THANKS for posting this, @bullrider!

Given the high number of threads here on the topic, I'm susprised your post seems to have been ignored for more than a year.

FYI to those who find this moving forward, the iJDMToy "Special LED Daytime Running Light Decoder Wiring Relay Kit for installing LED bulbs on high beam as DRL lamps" product works well, and it's so fairly priced (arrived in a few days for under $20 including tax & shipping)!

Here's a series of captioned photos (from another post I just made on the topic):

'Generic' LED 9005/HB3 lamps lit up in lower-voltage 'DRL mode'. Headlight switch set to Auto.


Headlight switch ON - lowbeams (still halogen bulbs installed). LED Highbeam/DRL turns off.


Headlight switch ON - highbeams. LED Highbeam/DRL goes bright!

 

Hey guys, sorry I'm new to the club, I love the lights, I have the GS350 F model, which has a beautiful set of headlights, can you tell me how much and where are they build?

 

My DRLs are inoperative but the high-beam function is working. Bulbs OK. Replaced the two relays, cheap and easy access. Still no DRLs.

Where is the DRL resistor located? I know the manual says its on the driver's side of the engine bay. Cannot see. Is it under the battery tray or under the fuse/relay box behind the battery?

 

As I recall, when I installed the iJDMToy.com gizmo, that this thread is about, I never had to locate the stock DRL resistor... just plugged-in the "Special LED Daytime Running Light Decoder Wiring Relay Kit for installing LED bulbs on high beam as DRL lamps" as instructed and it worked :-).