The hyper flash is the problem when change the turning light to LED bulbs, the most popular solution is to add load resistors onto the bulb harness, but it has cons I think:

1. Need to cut into the turning light wires to connect the resistors. There is a type of resister coming with the bulb connector harness on the market to connect the resistors and the LED bulb without cutting the original wires, but it cost over 50 dollars for 4 bulbs.

2. Have to find a place to mount. The resistor will draw about the same amount of power as the filament bulb does it would create lot of heat, so it needs to be mounted on to the car body to dissipate the heat. For GX460, this could be a challenge.

3. There will be no bulb failure warning hyper flashing function anymore, although it could be very rare to happen.

There is another type of LED bulb which has the load resistors built inside the bulb, this kind of LED is called as LED bulb with “decoder”. This solution also has the same problem of heat dissipation, the small heat sink on the bulb, when the bulb working for a while, it would get really hot.

There is 3rd way, a 3rd party LED flasher to replace the GX460 flasher, but you have to do lot of re-wiring to make it work. Some of the original flasher function could be lost.
So I am going to go with a better solution - modify the GX460 flasher, the goal is - no wire cut, no heat problem and no function lost, everything is the same as original.
The idea of this solution is to change the shunt resistors inside the flasher, that would make everything clean and full functional with the lowest cost.

First thing I did is to order the LED, searching on Amazon, found a seller: iBrightstar, the “#1 Best seller” LED, it has 54 3014 LED chips around the side & 3 3030 LED on top with lens.
It surprised me that the current on each bulb is only about 80-90mA (about 1 Watt per bulb), so much less than they specified 300mA – 4.8W. Then I ordered another pair from anther seller, it ended up the same thing – false specified.


The GX460 flasher, model number: 81980-60160

The GX flasher is behind the mirror control button switch module, you can remove the panel with a plastic ply bar to pop it up and then you can see the flasher. Remove the wire connector and nut with 10mm wrench.

The flasher cover clipThere are two clips on the flasher cover, tilt it up to remove the cover and the PCB board can be sided out.

The GX460 flasher PCB and shunt resistors

There are two resistors need to be replaced. Remove them from the board, they are really tight on the board so I took a while to de-solder them from the board. I found a better way thereafter that could be much easier to do: Instead of de-solder it out, cut the resistor directly and leave 2-3mm on board, then the new resistor can be soldered on those “legs”. The red arrow on the image above is the place to cut.

As I don't know what voltage the shunt flashing threshold is, so I have to try different resistance. From 1 ohm, 0.5 ohm to 0.25 ohm, none of them worked, the LED flashes once then went off even I was keep turning the signal. so I have to order more resistors and waited 3 days to continue the testing. Finally, the 0.2 or 01 ohm resistor works perfectly, and I picked the 0.1 ohm for less power consumption.
If any of the LEDs is failed (I tried to pull out the LED), it can trigger the hyper flash warning as original.
The total cost of the solution is 4 LEDs and 6 dollar resistors (got 30 in a package). This is the cheapest, safest, and full function reserved hyper flashing solution.


shunt resistor replaced

Note: The 0.1 ohm resistor can be ¼ w, 1W or 2W. And you need a soldering iron.
In case of you may fried it during the modification, the flasher part number is 81980-60160, equipped on 2010-2020 GX and 4Runner. It cost 50$ from Lexus dealer or Lexus parts store, and used one is 30$ from eBay.

 

Nice job, I went with option one when I upgraded my lights to VLEDS about 5 years ago - cut into the turn signal wires to attach the load resistor, and attached that to the body of the GX. Still works amazingly till this day, it's still very bright. However, let me get this straight. You weren't comfortable with cutting wires to attach a load resistor, which I believe is the simplest and quickest solution, but you were ok with ripping out the flasher on the GX, then seeking out a whole bunch of parts, de-solder and then re-solder resistors onto it? Hey, at least you retain the hyper-flash option whenever those LEDs burn out. I simply check all of my lights from time to time. What happens if you upgrade your LED lights to a bigger and brighter unit, which may draw more power. Will it still work with your setup?

 

Load resistors are not ideal to say the least and are a potential fire hazard IMO. I bet that flasher could be modified like I did here
https://www.clublexus.com/forums/per...l#post10935174

What this does is feed constant voltage to the load sense pin instead of sourcing voltage across a load resistor. This way no matter what bulb you use the flasher still works. Downside is if there is a bulb out no hyper flash. But nice job way more elegant solution that brute force load resistors. BTW, listings for LEDs that give some high wattage number that is all marketing people see a bigger number and think that must be better.

 

From the current LED bulb on the market, I think there is no big different on the power consumptions, they just all marks the higher power that get buyer happy. This is because the LED industry makes the LED chips higher brightness with lower power.
The bottom line is that, the 0.2 ohm resistors is working as well, so even the power could be more than 3W, I don't believe it as a 3W bulb would be as bright as the 40W filament home light bulb, the turning LED bulb on the market never be such bright.
You can measure your LED yourself if you have a multimeter, put the multimeter on 600mA, put one probe on your GX460 battery and the other probe touch the LED leg, put the other leg onto the battery positive post, then you can read the current draw. Then you know what is the power draw on your LED.
The worst case, assuming the current draw would be 3 times more than mine (90mA) - the most selling turning LED bulbs on Amazon, then the resistance would be 1/3 of the 0.2 ohm which is 0.067 ohm, close to o.1 ohm. So you can parallel two 0.1 ohm resistor when you soldering to make it to 0.05 ohm, that would work too.
As I did order the second pair of LEDs from another seller, the power draw is about the same as the one I installed. so 0.1 ohm should be working on most of the LEDs I think.

The resistor on my flasher is soldered through the PCB hole, but you don't need to de-solder the original resistor totally from the PCB which is very difficult without a hot gun, you can just cut it at the position where 2-3mm above the PCB, leave a leg there, the new resistor would be easily soldered onto the "leg", that would make the job lot easier.

 

This looks like excellent research and execution for the LED mod to be more OEM like rather than an after thought. Kuddos for put it together and sharing with everyone else.

 

For the size of the LED housing, with different LED diodes, the power won't be too much bigger due to the current semiconductor industry haven't been able to make small size super high power LED than current LEDs. The power comsumption won't be much different, it will be still under the flasher
detecting range. The reason I can tell is that, I tested 3 sets of different brand LEDs, they all market different power, but they really have very close
power draw from my measurement reading.

 

The thread identified the right part which helps in locating the part. Next just replace it with the Profile brand LED 5 CF18 LED Flasher Relay. Your done. Stuff works better than any other option mentioned.

Pick one up From theretrofitsource.com or sister Co. Headlight Revolution. There is another company that is much cheap but I can’t remember it’s name.

Highlighted in green

The module you’ll be looking for.