I agree, the results of using the different values seemed somewhat counter intuitive, but I was simply so elated to find the right combo to make mine work I just gave it a "meh" and moved on. The other head scratcher is that using the higher values .135 2w and on caused the flasher not to function at all.

jgarrido you are correct, the value will be different depending on what leds you have, but I cant imagine them varying too much as long as you have all leds.

 

Wow, This is getting very technical.

So basically shaving down the shunt resistor to a certain value using a volt meter, I can pretty much determine how much more I need to shave down until I fall within those values correct?

 

think installing two 13 6000k smd 5050 in my drl (2 bulb turn off) which means in turn have 4 bulb so I have to shave in a bit the shunt.
ok Pw = E x I, E = a constant voltage is 12v and I = is the current through smd if varies depending on the number of LEDs you have, this means that there is great difference between the intensity passes through the bulb and that of the smd.
In the relay, the shunt is a resitencia calculated to pass through it a current intencida x for 4 bulb, this current flow x sets a reference voltage value (Vr)
when a bulb is opened (off) this Vr varies(in relay) because the current flowing is smaller and a hyper flash appears, indicating a light off.so which the relay is now with the smd having low power supply, a lamp is off

 

hey guys anyone has the diagram lexus relay .
rcjten .135 ohm resistance is much lower than 0.18ohm, I recommend you try with 0.15 ohm 2w( no other parallel rest)and checks the blinking, from this value starts to rise (0.16,0.17,0.18) to achieve the correct flash.... good luck!!!

 

Hey guys... So I took it upon myself and tried the method VLED had in its article.

It actually worked.

The shunt resistor was shaved down about a little less than half way. It took me three tries and I can confirm all lights are now normal and I still have my lock notification. I tested the lights as well while off, car on, headlights on, car on, etc... no problems as of yet.

 

Nice work! Is your shunt resistor copper? Mine was a silver metal. Have you measured the resistance of the shaved shunt?

 

The resistor was silver in color. Some what of a soft metal. Easy to shave down.

Believe it or not I wanted to measure the thickness using a digital caliper and a voltmeter but both of the tools were out of batteries .. You can shave off quite a bit before you even start testing it for the first time.

 

aggatek, let us know the resistance of the shunt after you shaved it. I'm curious to know. I may do this later today and measure this myself but it'll be interesting to see the value that you get.

This thread is great! I love the fact that you guys are doing research and testing with the IS. I like seeing this since I first started with a Honda and the mods are always being done to something or another.

For those of you interested, here's a resistor calculator for LEDs. You plug in the values of the bulbs and it gives you the recommended resistance value. But this will depend on how the bulbs are wired (i.e. series or parallel) and how many you have. Much of these values can be found on the bulb manufacturer's website (vLEDS, superbrightleds, etc.) But this calculator can only be used if you're planning on removing the shunt and wiring in your own resistor.

http://led.linear1.org/led.wiz

Keep us updated. Great job so far!

 

So I finished it and it worked. I took me about 10+ tries since I wanted to be extra careful about shaving it off. My shunt was a silver as shown below. I thought I would never get it shaved down enough since it was getting fairly thin. I had to take off about more than 1/2 of it...it was down to about 1/4 remaining, like the vLEDs bulletin mentioned.

But I got it to where it would alternate between the slow and fast clicks. Taking just a hair off of the surface got it to the point where it stayed at the normal frequency.

I measured the resistance with a meter and the best I could tell was it was between .1 and .2 ohms. My Fluke meter wouldn't read anything more precisely than this. Sorry this isn't much of a help.

Maybe the pictures show how much I had to take off. Good luck to all.

 

then confirmed,is only shaving the shunt.....good work!!

 

I got my new stock relay today and used the multimeter on the resistor. It is 0.6 ohms.

 

Tested last night.

I put a 2W 0.15 Ohm in there. Thought I had some hope but did not work - Basically what it did was one fast click flash and stopped working; verified with pressing unlock and hazard.

Possible reasons:
- All the LED's need to be present? Tested with all stock bubs in, the other with taking the rears out with no LED.
- The relay I got was the one designed for the 10 and earlier cars, and what I really need is the one for the 11+ car. However, if the two relays are exactly identical with the exception of the shunt resistor value, then it would not matter. If it does, I can just plug it in the 07 car since it uses that and put LED's in that one for kicks.

Good thing I have the stock flasher to plug back in and works as intended.

 

BUMP!

I know this thread is 5 months old from the last post.

But, I wanted to thank those that provided this information and to those that attempted this modification. I finished installing a pair of 2012 Headlights to my 2007 IS250 late last night and had the fast blinkers. (Even AFTER installing the needed replacement relay)

With my tail between my legs, I wanted to throw in the towel for the night and go to sleep frustrated.
But I ended up doing a search, saw this thread, and tried it on my old relay..... I figured I had nothing to lose.
First try! Boom, the flasher works perfectly!!

 

I bought the cree + led for my rear turn signals, wont mention the brand incase im doing something wrong, (top brand) still got the hyperblink wtf