LED hyper blink mod

For some reason after having already bought a relay that fixes the hyperblinking, I still scrounged the interwebs for instructions on modifying the OEM relay to accomplish the same thing.

After looking at Jeep tutorials and other brands that didn't really explain the why (how the circuit works etc) I found a custom taco thread specifically on our relay and extremely well explained and written.

https://www.customtacos.com/threads...d-turn-signals-without-load-resistors.138935/

So I did it using a .1 ohm half watt resistor.


Picture of the removed metal strip acting as a resistor and the new .1ohm in its place.


IMO this is the best mod- you keep the OEM relay and the hyper blink feature, just tuned now for LED power draw. You do not have increased power draw of external resistors- and this mod is free for most people, or under a buck going the internal resistor mod.

 

I wonder how many could do that I work with a few that can`t solder.

My flasher from Napa works fine Did the go to a 4 pin relay in the newer trucks ??

 

In my searches the newer trucks have like 12 pin or something crazy like that. Mine is a 2001, 3 pin relay.

Yeah I have a solder remover suction thing and a really good soldering iron. I think it's the stay at home thing, I couldn't leave good enough be. Just wish I did this before buying the relay as that was a waste.

That said, if someone needs an LED relay in the SoCal area, I'll give it to them.

 

I'd just get an electronic flasher. It uses a timer ic instead of a calibrated bimetal strip.

 

Have you installed this part?
I like the idea

 

I have not. But from an electrical engineering standpoint, it makes a whole lot more sense - no extra heat, and constant blink rate no matter the load.

 

That's what I like about the mod approach as hyperblinking is a feature, it lets you know you have a bad bulb or in this case an LED gone bad.

The resistor mod on the OEM relay is not to be confused with the load resistors people use that draw a lot of current. It can be a 1/4 Watt resistor as it's just changing the calibration of the IC in the relay circuit.

Going to .1 ohm makes it setup now to not hyperblink with LEDs, but if one goes bad it will hyperblink.

 

What's the typical failure mode for an LED bulb gone bad? Is it the same as for an incandescent?

 

Taken from the customtaco thread:

The stock relay is setup for incandescent bulbs. The front and back set (left set or right set) draw about 4A total (2A per bulb). If one bulb dies then you only have 2A. They put the hyper flash trip point near 3A (high enough you won't get false triggers, but low enough to catch a bad bulb). When less than that current flows the voltage drop across the resistor falls below the fixed 80mV trip point for the IC (80mV is set inside the IC).
For example, lets say you are using front and rear LED bulbs for turn signals. These bulbs draw about 1/2A each for 1A total. You want the trip point to be above 1 bulb, but below 2 bulbs so pick 0.75A. Now a little ohms law. (0.75A X resistor value) = 80mV. 0.75A / 0.08 = 0.11 ohms. Call it 100 milliohms. Replace the resistor with 100 milliohms and you should be set. Use a resistor rated at 1/4 Watt or higher

 

So it only detects if they fail open, which is ok I guess. But you also have to make sure the new resistor value is calibrated specifically to the bulbs you installed. I was looking at 1156's from super bright LEDs and they are all between 0.14 and 0.22 A, which is 0.28A - 0.44A total, and would trip the above modified hyperflash unless you went with a 0.25 ohm resistor.

Is the light out detection enough to warrant the extra fanagaling? Not for me, especially since LEDs last a very long time.

 

Yeah this mod isn't for everyone, but I like that there are options and as you demonstrate customizable to specific setups. One online tutorial the person put in a tiny rheostat, which I might do later cause I like to tinker with this stuff. As far as fanagaling to each their own- some do stuff here that is "easy" to them and I'd rather go to a shop, and in this case I do a lot of hobby electronics so was easy to do this.

 

You can just grind some material out of that strip instead of replacing it with a resistor.

 

That's what the original linked tutorial calls for. In my case with an adjustable Weller and solder suction pump honestly easier to swap out to a resistor.

Teh pump next to the relay. This things are awesome at sucking the solder right up.


And then like @0xDEADBEEF showed, look up the amps of your setup and choose a specific value to keep hyperflash feature vs just brute force.

 

That was a pretty good thread
She is still working great 11 years later. Not sure why your replacement LED specific flasher didn't take care of it for you, but tinkering is a lot of fun.
Matt

 

Yeah I have no issue with the mod itself, just want people to be aware of the implications and pitfalls. It's certainly a better workaround than adding resistors to the LEDs themselves.

I was wondering as I was laying in bed through - how did the electrolytic caps look in there? Eventually they're gonna dry out or leak. If it starts acting funny, that'll be a good place to look.

 

Ah snap the man, the myth, the legend himself! Didn't know you were here too. Again great post, it explains the why, how and pros of this route.

The aftermarket EP35 did work but as I looking at the OEM relay thinking about tossing it into the OEM parts box and it nagged at my brain, "someone must have reversed engineered this circuit".

I'm a big fan of OEM so when I found your post I was stoked- keep OEM and it's not "brute Force" like some 555 timer circuit that has no load context. If I change out my rear inconsecents I might try to find a small rheostat to use in place of a new resistor. Maybe have to make a parallel resistor with it to give it the range and granularity desired.

Like you said, it's fun to tinker.

And that leads to my above, they look great! I'd take a 20 year old Toyota denso made cap over this new crap any day.

If issues arise I have the EP35 from 'itoyjdm' or whatever to fall back on, but I expect this oem part to keep on ticking in fine older model Toyota tradition.

 

Toyota flasher is electronic. Bimetal type flashers are long gone.

There is another method of modifying Toyota flasher: described five years ago here: https://www.tacomaworld.com/threads...replacement-comparisons.393583/#post-11107745

You may start reading from this: https://www.tacomaworld.com/threads...replacement-comparisons.393583/#post-11104636 - some technical info about Toyota flashers.

 

Where does the EP35 relay plug into? I picked one up awhile ago but don't know squat about the electronics on these trucks, except that it goes somewhere near the fuse kick panel in the cab...I think.

 

The question has been asked and answered in the same thread : https://www.tacomaworld.com/threads...replacement-comparisons.393583/#post-11106877

 

For the longest time I thought I would have to un-bolt the body ecu/fuse box to flip it around but like others said as I searched around it's simple just getting down on the deck and reaching around to the back top of the body ecu