Hi.

I came across thread with DIY LED harness for TL, but paying anything over $20 for couple wires is not my thing. I must say that other approach is cleaner, mostly because it's easier to revert back to stock. BUT my way is cheaper. If you have wires, insulating tape, and couple zip ties, then total cost is $0 (not including LED bulbs).

Canadian TL might be different. Find schematics for your car or test everything with multimeter !
As far as I know it applies only to 2007-2008 USA TL.


So what you might need :
- two LED HB3 bulbs ( )
- some wire
- 2 same value resistors (rather high, I went with 10kohm as I have plenty of them)
- soldering/crimping stuff, insulating tape/heat shrink tubes (to connect wires together, whatever you prefer, soldering FTW)
- 10mm socket (to remove battery, and optionally radiator mounts)

How it works? Look at the schematics.


Two bulbs are connected in series, making them run on 6V each. If one bulb breaks, other doesn't work as well. Between them wire is split and "goes to the car". If there is ~6V at that wire, car knows bulbs are ok. If there is either 0V or 12V, one of the bulbs must be broken, and yellow "DRL" lights comes ON on the dash.

Instead of the two bulbs I'm gonna use voltage divider, made of two same value resistors. I tested it before. Here I'm using one DRL connector, with two 10k resistors, other connector is not connected to anything :

Don't trace the wires. I'm just saying that I tested it and it works. No bulbs are connected and "DRL" light is off.


That is basic concept :



I decided to work primary on the right (passenger) side, as I have 12V, ground, and middle (blue/black stripe) wire easily accessible.

Yellow from bulb connector is 12V line.
- remove insulation and connect is to one side of voltage divider
- also add extra wire that will go to other side as 12V supply

Ground - I used black from HID igniter
- connect opposite end of voltage divider

Cut blue wire from bulb socket.
- Blue wire end running towards the car must be connected to the middle of voltage divider (two resistors in series).
- Blue wire from bulb socket must be connected to the ground.

Now left side of the car (driver's side) :
- black wire stays as it is ground.
- blue must be cut, end from the bulb connector must be connected to the spare wire connected to yellow wire from the other side
- blue running to the car must be just insulated/secured and left not connected

How it should look :


Driver's side :


I ran that black wire from passenger's yellow in front of the radiator, using zip ties to secure it to wire that already runs there. I removed two bolts holding radiator's mounts to move it towards the engine for more room.

Done !

Hopefully it's not too much confusing, as whole mod is really easy.


Both bulb works like stock ones, and there's no yellow "DRL" message on the dash.

 

Sorry I don't follow how the yellow wire is 12V

 

 

The yellow wire gets 6V not 12V.
Let me put it to you this way. Just because you see a line going to the battery in the schematic does not mean it gets 12V.

You really think you had something there didn't you

Really though, nice try.

 

I'm still not sure if you're joking or not.

It works.

Bulbs are 6V each as they are connected in series.

Exactly like on the schematics.

Unless my LED bulbs works at 6V.

 

Now you're catching on.

Your LED bulbs are working (with half power) at 6V. Some bulbs won't light up at all with 6V, yours do.
Sorry, been messing around with you. I'll cut to the chase like I should have on my first post.
There's a reason why DRL harnesses for our car include a relay. It's so you can get 12V to the bulbs.

Here's what you should do to get 12V because you don't seem to worry about hacking up the OEM wires.
Buy relay. Put the yellow wire to pin 85
Put wire from pin 86 on relay to body ground.
Put wire from pin 30 on the relay to the battery positive terminal.
Put wire from pin 87 to the + wire of the OEM 9005 connectors.

I'm all about saving money, but the iJDMToy harness is the way to go. People will pay the $30 or so not to hack up their OEM wires.

 

So why they would make schematics like that? Also how car is producing 6V ? Is there some buck converter type of thing?
Why blue wire has 0ohm continuity between one terminal on left and another on right side?
Why blue wire has no voltage between + or ground on the battery when both bulbs are disconnected ?
Why my voltage divider works? Especially when I "tired" it on with negative wire, two resistors and directly to the battery?

I'm gonna pull one connector out tomorrow and measure voltage between terminals.

So either you're not right, or everything that I did wrong miraculously worked out, and I'm back where I started.

 

Wouldn't it be easy to determine if yellow is indeed 6V or 12V? Isn't there some sort of meter that would determine the voltage.....

 

 

Buck converter? No... there's circuitry between the bulbs and the battery if you look at the schematics.
Did you miss the MICU?

I may be wrong about it being 6v but MICU reduces half power to the DRL bulbs. Measure your current and I'll measure mine

There's a reason why VLEDs and IJDMToy use a relay in their harness... think about that. It's so the bulbs can run at full power and not half power.
If their goal was to just get rid of the error, you can just use load resistors.

DRLs NEVER come from factory to run at full power, typically half. You'd blind everyone essentially since it'd be like high beams.

 

For me it looks like it doesn't go into the MICU. Just into fuse box, and thru 15A fuse.

If I would check for resistance between + and yellow with key on it will be probably 0ohm.

Disconnect one bulb. Other one should be out as well. They are in series, powered by 12v, making them divide the voltage in half (assuming they both have same resistance when lit). It's simple setup. Making any voltage/current regulating device for something like DRL is just overkill.

You want to measure current with Led or standard bulbs? Current on yellow wire?

 

Yup, let me know your current on the yellow wire.

Sorry man, I just have a hard time believing you turned a DRL wire from the factory to run at full power without a relay.
If you did, you gotta be published or something because thats incredible

 

With only one side, as other is harder to reach.

 

Thanks for posting. I just went out to try and measure current but I don't have a clamp meter so whenever I unplug the iJDMToy harness resistor both my DRL lights go out and I get an error on my dash.
If you have time to check it out and see a difference in brightness, hook the LED bulb up directly to the battery.

I think I'll just wait for others to chime in for now

Again, I may be wrong about the wire not being 12V (as evident by your multimeter) but I do know that the car computer makes the bulb not run at full brightness.
On cars that are not Bi-Xenon, the DRL and High beam run on the same 9005 bulb. DRL is always run at half brightness and when you hit the highbeam, the MICU sends out full power to the bulbs so they run super bright.
Since our car is bi-xenon, the 9005 bulb is just always run at half brightness. Running DRL during the day with full power using halogen bulbs is overkill (which is why car factories don't do it), but with LEDs it's not - you want full brightness with LEDS because in bright sun LEDs are harder to see.

 

It's same as radiator relay. When fans wants to run at half speed, both fans are connected in series.




There's Amp draw of standard bulbs at 6v and 12v. Just to compare to draw from the car.

 

i'm not super smart with electronics, but i do know that without a relay you wont' get full power to your led bulbs for the DRL. some people can hook up leds straight up and not worry about the DRL error dash, but it's well known that those leds won't be having full power without a relay

i'd like to see more discussion with people smarter than me and see where it goes tho!

 

So if I hook up both standard bulbs, and get 5A on each of them, you guys gonna believe me?

Unless you have different models. I don't know how they did it on Canadian version.

 

The op is correct, the yellow wire is 12 volts. It's all 12v through the relay and the first incandescent light bulb but changes to 6V after the second incandescent light bulb because it's wired in series. Referencing his first diagram above.

The relay for the DRL only acts as a switch to turn on the current to power the DRL. If there was no relay the the DRL would be on all the time because the circuit is wire directly to the 12v battery.

LED will only trigger the dash warning light if it's not 12v. There are two different styles of LEDs. A 12v and non-12v LED. If you use a 12v LED (SMC) then it's plug n play. Other LEDs will need a resistor to restrict the flow of current so it can reach 12v by slowing down the flow of current.

 

Finally somebody on my side. Hah.

BTW it will trigger warning light only when there's something different than 6V on this blue wire between the bulbs. No idea if it measures to the ground or positive. I used voltage divider (two same value 10k resistors) to simulate it. Blue wire is connected only to the voltage divider now. Refer to the second diagram

 

Thanks for exploring this option, I think I was blind to how the schematic diagram works.

Any pictures of the car with the new LEDs?

 

Pretty cool.
So much wiring involved, I doubt anyone will go ahead and try to complete this task when there are plenty of harnesses out there.
Good DIY though.

 

what are you talking about there ARE tons of harnesses out there... What' Peter is trying to do is NOT use one of the aftermarket harnesses because he has the technical aptitude to delve into the wiring diagram to re-wire it to do what he wants

 

OP, 10kohm at what watts ? and here is the actual calculation based on the Voltage divider formula.

 

What's up guys. Apologies if it's not the right thread...
I bought these lights for my DRLs CougarMotor 9005 LED Headlight Bulbs All-in-One Conversion Kit,7200 Lumen (6000K Cool White) https://www.amazon.com/dp/B01H6NZ6F2/ref=cm_sw_r_cp_apap_QmK1AMLetv7Xn

They're extremely bright, even on sunlight, however they spontaneously turn off and on when I'm not using the a/c. Should turn the a/c on - the lights work perfectly fine, no flickering or anything... Any idea what's causing this? I got the same lights for my wife's TSX - no issues at all.

 

EDIT: I'm assuming your using 10kohm at 100w on each resistor.

 

I'm using two 10k 1/2 watt resistors. There's almost no current flowing (around 1mA) so 1/2 watt is enough. Car checks only for the voltage on that middle wire between bulbs.

 

Ha...I was thinking the original circuit need 180w ( 12v x 15A) but the more I think about it you only need the "Voltage-6v" to trick the ECU..... OK got it.

 

Send me a link I think I might need that kit. Thanks

 

I too need this kit but iJDMToy no longer sells it. https://store.ijdmtoy.com/pages/9005...allation-guide
Emailing them got me this response... "The DRL/High Beam kit will work on your vehicle as long as your OEM DRL bulb is a 9005 bulb size. You will also need the R4 DRL decoder for the LED lights to work properly. However, this has been tested for compatibility for US models only so we are not 100% sure how it will work on the Canadian model." I have a Canadian model and the link they supplied leads to "404 page not found".

I'm considering a couple of Amazon options but would appreciate any input or recommendations...

Alla Lighting 9005 9006 HB3 HB4 9012 50W 6Ohm Error Free LED Light Load Resistor Adapter Fix Flashing Blinking Canbus Bypass Wiring Harness Decoder for Headlight Headlamp Daytime Running Light

 

I just bought my kit fromjdm and they upgraded because pics look different. Easy hook

 

order from vleds. that's where i got my kit from and it's much higher quality than other company kits i've used in the past including the company you mention

 

AMI8 - the kit that you linked is simply resistors parallel to the bulbs. The idea is to increase the load on the system. That would work if car would be detecting DRL function via measuring current going to the bulbs, which is NOT the case in TL.

 

So if I understand you correctly my setup (2005 Canadian TL with seperate DRL (not combined with high beam / low beam headlights) with swapped in 9005 / HB3 LED fog light bulbs (1 LED = nice bright light; 2 LED's = no light. No DRL warning light in either case.) will need a harness like iJDMtoy.com's https://store.ijdmtoy.com/collection...adapter-aa1180


If that's the case I don't know why iJDMtoy.com couldn't just send me that link in their reply email. I know it's only $10USD but an easy sale's an easy sale.

 

So after sending a second email to iJDMToy I received this reply, "This 9005 relay harness is only for add-on fog lights, LED work light, xenon LED conversion, daytime running lights, etc.

We currently do not have an LED DRL decoder setup compatible with the 2005 Acura TL. We do apologize.
Cheers,
iJDMTOY.com"

If anyone knows of another reliable retailer please lmk. Thanks.

 

If you get some wires, two male and two female 9005 pigtails and two 10k 1/4 resistors, an soldering iron, and have some free time, then you can make one yourself. Just like me, but without cutting car's wiring.

 

So i have tl s 07, bought leds 9005 for my drls, quickly found out i need one of these kits, i wanted to know if theres any plug and play harnesses out there now since this thread is from 2017. If there isnt then i wont have any choice but to look for those dyi harness

 

There used to be at least one. Link doesn't work but maybe you can still find it on their website.
https://acurazine.com/forums/third-g...w-pics-853543/

 

i got mine from vleds and it's been super reliable for years

 

Which one did u get? They have cancellors and load resistors

 

I got the R3 kit from them