G-109: DIY-Eliminate LED Bulb Induced Hyper flashing WITHOUT LOAD RESISTORS
 

I know everyone on here running some type of LED signal bulbs is running some kind of load resistor to eliminate the bulb out warning system which causes "Hyperflashing". Due to the very low energy consumption of LED bulbs 300-900 mA (.3-.9 W) per LED bulbs depending bulb to the huge 21/27W 1157 incandescent bulb! Thats almost 90 times less power!

So now we take all this energy savings and throw it all down the drain by adding load resistors that basically take all this energy and convert it to useless heat to fool our car into thinking we are still using a 21/27 W bulb. While I know we don't swap in LEDs for energy savings, and our electrical is run off the alternator we dont really notice it.

Well recently I switched to LED signal bulbs and one thing I knew for sure using load resistors was going to be a last resort. Instead I turned to the cause of the hyper flashing, the turn signal relay itself.

Many cars use simple analog relays and have many aftermarket replacement options that correct hyper flashing without load resistors. Lucky for us our flasher units are a bit more sophisticated and are run by a micro controller without any aftermarket support that I could find.

After opening our existing turn signal relay and some research It was a successful mission! I pulled the data sheet from the IC on the relay circuit and found this info below. Basically a resistor is used to sense whether or not you have a bulb out. By changing that sensing resistor you can change the point at which hyperflashing is triggered.

"Lamp Defect Detection (Pin 7)
The UAA1041 operates with a 30 mΩ shunt resistor to sense the lamp current. It’s lamp defect detection threshold of Pin 7 is typically 85 mV"

http://www.datasheetcatalog.org/data...a/MC33193P.pdf

After some math and some other research from a similar project on an RL I ending up with a .12 Ohms 1 watt resistor as the replacement. This would result in normal flash rates for the following scenarios:

[2] regular filament bulbs running - if one filament fails, no hyperflash. If both fail, then hyperflash
[1] LED and [1] filament bulb running - if LED fails, no hyperflash. If filament fails, then hyperflash
[2] LED bulbs running - if one or both LEDs fails, then the unit will invoke hyperflash

No videos but take my word it works perfectly!!!! Very cheap, less strain in your alternator, and a truly useful advantage is you have less of a chance running your battery down if your sitting at a car meet with your parking lights!


Here are the pictures!!!

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P.S. I did this on a 2006 TL, the 07/08 might have a different flasher unit because of the side mirrors I'm not sure. If it does post some pics of the IC. The .12 ohm resistor should also work, as the sensing current has been similar in other Acura's using completely different relays.

Oh and standard precaution proceed at your own risk!


This one has to go in the Garage!!

Excellent find and research, Roger555.

It'll become very useful for me in the future =)

You're a genius...

to be honest, the 6.99 for resistors seems to be much more easier lol.

not bad...i will consider doing this seeing as how I have access to an electronics shop with all kinds of soldering equipment. can someone confirm that it works on a 2007 tl-s?

i only need a .12 ohm resistor correct?

Very cool. This might convince me to move to LED blinkers some day.

^ This.

I like this approach. Seems more reliable. So you install that resistor by soddering it onto the board from the other side?

This is one seriously of the easiest mods I'v had to do. I don't know about you but I'd rather have a proper fix then a band aid fix like a load resistor, even if it did like me longer to do.

Pop it out and take a look, it only takes a minute to get out out. It just clips in the fuse box you may need a standard screwdriver to undo the clip on either side as you pull it out.

Its much much better then load resistors, and yes just solder the legs in from the other side.

nice..I will have to check this out.. right now I have the resistors for my switchbacks

Yeah so do I in the back. So Roger essentially I can remove those resistor for my switchbacks? and I can also add lleds in the rear signals with no worries? This of course on a '08 TL-S. Just my luck too I have that relay as an extra cause I thought mine got messed up before so I can tinker with this.

So what would happen if you were to put the stock bulbs back in? (not that you'd want to) Would they just blink slower?

Yes it should work but you should open up your relay and see if its the same as mine.


No basically there are 2 modes normal rate or hyper flash
Pretty sure If you ran regular bulbs it just wouldnt hypeeflash unless both your bulbs burned out.

Yup I saw that thread, not the same relay but the current sensing specs are similar so .12ohms seems to work for a few different types of Honda relays.

Someone check to see if this works for 07/08 TLs.

Roger, great research; recently i've been working with circuitry including resistors and inductors in the physics lab.

Definitely a great alternative if you're not a fan of 'multiple wires' behind the headlight--I definitely am not.

It does seem like more work than the 6 ohm resistor, but definitely much more clean. I might try this one day.

I keep hearing more work! but literally the relay is in the kick panel next to your feet, you don't have to remove anything just get down there and grab it! Pop the cap off (5 Seconds), Soldering 2 minutes tops, pop the top on and stick it back in, 10 Minute job and you didn't even have to do the research!

To install Ohm resistors you need to find a good spot, usually in the back seems popular. Pulling the trunk liner back alone is more work then this project. Then you have to Drill mounting holes (If you want to do a good install) and tap the wires.

Maybe its the soldering "Mental block? that throws people for a loop on this one. My solder iron is in constant use so its second nature at this point I guess.

But what if you get 12V LEDs? No need for this and no need for resistors. Because that 12V LED bulb will have the same voltage as a normal bulb.

We are taking about current (Watts) not voltage, two closely related but completely different things.

Everyones LED PNP bulbs are using 12 volts right now (more like 13.5 average from the alternator). Depending on the design of the bulb itself its circuitry will either use resistors or voltage regulators to dissipate the excess voltage as heat.

Basically your LEDs are taking in the 12volts but they are using less power therefore they draw less current from your electrical system. With the drop in current your relay will activate hyper flashing.

Conclusion: Its the lack of current draw that your relay senses nothing to do with voltage

Where can you buy the .12 Ohms 1 watt resistors? A quick search on Radio Shack's website didn't yield anything. For something this cheap and small, I'd rather just get it in a store than wait for shipping.

This looks like a good alternative to those resistors. I was going to order those things and mount them in the trunk, but looks like there is an alternative. I'll just wait and see if this mod applies to my car too.

i completely agree with you that this is an easier task than using resistors at the headlights. most people are turned away at the fact of soldering but its actually really easy.

I ordered mine at digikey there was like a 10 piece minimum so I got 10 for like $3.66.

As for shipping Digikey offers shipping for 1.90 for small orders, I bought them on sunday got them on Tuesday. I know that sounds painful but you wouldn't be buying your load resistors locally would you?

http://parts.digikey.com/1/parts/169...r-52-0r12.html

I agree with Roger guys this method seems so much easier and faster. I did my resistors in the trunk and it was a task having the clear the trunk then pull the liners. Pulling this relay is simpler to do, hell while you're pulling it you can be heating up your soldering gun at the same time. I'm gonna get my extra one and check it. I'll snap a pic of it opened as soon as I do it.

here's mine and it seems to be the same as yours is Roger...
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Hey Roger send me a resistor I'll send ya a buck for it for the shipping and the resistor that should be fair lol!

Glad there are a few bright ones out there! Not only is it easier its the correct way to fix the problem!


PM me your address I was actually going to offer to send you one.

Hey roger.. want to hook a brother up and help me do this? Dont have a solder iron handy. I'm sure tyler would be interested in this as well

Rog I do believe you have cornered a market here!!! mass produce them haha!!

For sure get ahold of Tyler you guys can stop over whenever he's been to my place a fee times.


Ha I would but this forum doesn't really make small ventures possible with its vendor rules.

This is a great find. I'm just suck with a soldering iron!

excellent write up. i would have done this mod if i didn't already have resistors installed.
currently working on swapping all the interior buttons to LEDs, so time consuming!!

Hey Roger thanks for the info. I have LED's in my front turn signals and need to install resistors. This methods seems much, much easier. I have a sodering gun in my tool cabinet. I was give it a try here in a couple of weeks. Will let you know how it turns out!

i need one of these resistors. PMed

Hey you guys that have a FRY's it looks like they carry it in some of there stores

http://www.frys.com/search?search_ty...bmit.y=0&cat=0

im gonna check out my local frys probably tomorrow or saturday and see what i can find...

my local frys says they didnt have it but i will check in stores myself to be sure. also, can someone confirm what wattage is required? having a wattage too low will lead to a failed resistor

just took out the relay in my 07 TL type s and its the same as the one in OP. so now its confirmed all 04-08 TL, base and type s, will all benefit from this mod.

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