OEM LED conversion harness DIY info

This is intended to be an informational thread on the parts needed, along with links to source them, to fabricate a conversion harness for a Pro, OffRoad, or Sport 3rd gen Tacoma equipped with halogen headlights when purchasing the OEM LED headlights offered on 2020 and newer vehicles.

If you are looking to purchase a pre-made harness, my personal recommendation is avoid TRS's option as it is a cluster. As of 4/22/2021 the best options as I see it are

1. $50 2016 - 2020 Tacoma Full LED Headlight Conversion Harness
   This eBay listing ($49 for both sides, unbeatable price, users report good quality)
2. Mike (xrunnerdude67@gmail.com) priced at $85, formally blocked from TW due to being unresponsive to emails but I run his harness, it's top quality, the guy is legit and if you are patient you will get your harness.
3. My own BST thread for my version of the conversion harness with integrated grille light feed priced above all other options.

If all you desire is the cheapest possible way to get OEM LED headlights installed on a vehicle and you don't have any qualms, warranty-wise or otherwise about cutting up your OEM wiring harness, you can go directly to this post from @caribe makaira for the hack-and-slash option.

If you have an SR / SR5, refer to post 2 in this thread.

Credit to @Puppypunter and @caribe makaira for all of the information presented here, I am merely the curator.

Tools:

1. Crimper (you pick) suitable for 18 gauge wire

Connectors:

1. Molex MX150 connectors (qty 2) *female* 33472-0601 15320 02
   1. Corsa-Technic @ 2.29 each with pins
   2. Waytek @ 1.23 each
   3. Custom Dynamics @ 4.95 each
2. H11 connectors (qty 4) *male*
   1. $8 UTSAUTO H8 H11 880 881 Male Socket Adapter Connector Wiring Harness for Headlight Fog Light Retrofit or Installing LED Light Bar LED Work Lamps (pack of 4)
      Amazon 4 pack w wires $7.64 -- depin before using
3. DRL connectors (qty 2) *female*
   1. Corsa Technic @ 5.71 each
4. Turn signal connectors 90980-11486 (qty 2) *male*
   1. Corsa Technic @ 3.66 each
5. Sidemarker connectors to seal unused OEM leads (qty 2) *male*
   1. Corsa Technic @ 4.49 each

Pins (match size to the wire you use, 18 gauge recommended):

1. Molex 33012-3002 MX150 pins (qty 12) *female*
   1. Waytek @ $0.13 each
2. H9/H11 pins (qty 8) 090II sealed *male*
   1. TBD
3. Turn signal pins (qty 2) *male*
   1. Corsa Technic @ $0.21 each
4. DRL pins (qty 4) TS 090II sealed *female*
   1. Corsa Technic @ $0.20 each
5. Plugs (qty 6)
   1. Corsa Technic @ $0.18 each
6. Seals (qty 6)
   1. Corsa Technic @ $0.22 each
7. H11 plug (qty 2)
   1. $0.17

Wire:

1. 18 gauge GXL in multiple colors $21.95

Optional accessories

1. Braided sheathing
2. vinyl housing
3. 1/2 inch flex loom
4. $12 Inline Tube 2 Rolls Factory Electrical Non Adhesive Wiring Harness Friction Tape OEM (J-10-9)
   Friction tape

Assembly instructions:

1. Cut lengths (6" recommended, customize as desired) for pairs of the following colors:
   1. Red
   2. Green
   3. Brown
   4. White
   5. Black
   6. Pink
2. Crimp H9 male pins on one end of each pair of red, white and black
3. Crimp turn signal pins on one end of each pair of brown wires
4. Crimp DRL pins on one end of each pair of green and pink wires
5. Crimp LED pins on the opposite ends of all crimped wires
6. At this point you may add any vinyl or braided housing as desired for protection.
7. Push the crimped pins from step 5 into the LED connector as shown in the diagram
8. Push the ends of the white and black wires into an H9. Note polarity as shown.
9. Push the ends of red wires into the remaining H9 connectors making note of polarity
10. Push the ends of green and pink wires into the DRL connector
11. Push the ends of the brown wire into the turn signal connector

For pin layouts I'm following the pin numbering @caribe makaira has in his post below which appears to be this convention:

1. From the back, pin 1 is top right then proceed right to left, top to bottom
2. From the front, pin 1 is top left, then proceed left to right, top to bottom
3. Top of the connector has the tab you press to release it
4. Therefore, the image below is looking at the connector from the front

Molex MX150 pin layout:

1. Red wire from low beam +
2. White wire from high beam +
3. Brown wire from turn signal +
   
4. Black ground from high beam -
5. Green DRL +
6. Pink Parking light +

DRL connector pin layout

1. Green DRL +
2. Pink Parking light +
3. Empty
4. Empty

For H11 and turn 2-pin connectors, I'm not sure how to clearly differentiate pin 1 vs pin 2 so your best bet is to refer to the OEM female plugs for polarity. OEM grounds are white with black stripe.

Confirm all colors match up with the OEM harness by using the driver's side to test. If the harness works properly on the driver's side it will work fine on the passenger side as well. NOTE that wire colors may differ on the passenger side.

Finish with flex loom and friction tape as desired.

NOTE: This is a work in progress and details will be flushed out based on feedback and future research. Specifically:

1. Add direct links to options for purchasing
2. Research options for high quality H11 male connectors

TLDR: Roughly speaking you'll spend about $40 on connectors, another $20 on pins and seals, $20-$30 on a crimper, possibly some extra costs for shipping, and $20 on wire making this a $100+ project if you come to it with nothing.

 

This post is directed at SR / SR5 trim levels which do not have LED DRL like the Sport, OffRoad and Pros do.

At this point in time, the recommendation is to review this thread for more information.

In the future, I hope to edit this post and lay out a clean DIY path towards OEM LED for SR/SR5.

 

Damn dude, nice work!

 

Is all you need parts wise. Wire cutter and barrel crimper for tools.

 

@Puppypunter has a solution for the SR/SR5 with the combo DRL/TURN bulbs that might work for the LED headlights assemblies.
Mine is "too much" for the non-DIY folks.

 

But mine isn't cheap I just need some brave soul to try it....
It is the same concept, but I used a HDRL controller from VLEDs to "split" the DRL and TURN signal into separate signals. It works well with the OEM LED as the DRL on them is also the turn signal, so basically a switchback anyway. The OEM lights just don't have the logic built in as the ECU does that for them.

 

@daveeasa Nice work BTW! Now, if someone would just sell them and back them up with some good customer service....

 

Have you tried out this harness? I currently own an SR and want to move up to using OEM LEDs and many people have sent me your way to test this out. I’m reluctant to mess with my trucks electrical components to say the least but i am still interested in upgrading to OR/Sport headlights.

 

Scary view for most here...

@Lt. Dangle & @metdfd can be pm'd for their "scary" story.

 

I thought it was pretty easy. And fun lol. Other than Toyota using similar colors for different things (come on), pretty straight forward.

I used the 2 pics in post #4 labeled passenger and drivers side of the wire color coding and went at it. I was more worried about scratching the new lights or breaking a tab off on install.

I accidentally locked one of the Molex connectors and had a few head scratching moments figuring out why the plug wouldn't latch, but once that was straightened out, no problem.

 

I have “tried” it The quotes make it comforting, don’t they? Let me explain: I don’t have an LED headlight to try it on, so I made a bench test “headlight” that is just led indicator lights hooked up via the Molex connection. I know the theory is sound, as I have used a variation converting SR to TRD function, and they worked great (had to add a resistor was the only hiccup, I thought the incandescent bulb would suffice. But with the OEM LEDs, you’re going to need a resistor for sure). That harness went to @ET22 if you want to ask him about it. Anyway, shoot me a PM if you’re really interested, and we will see what we can do! And I get being nervous, those headlights aren’t cheap. That being said, if you look at the TRD to LED harnesses, they are literally just redirecting 12V, same thing I am doing. Just using the HDRL controller to separate the DRL from the TURN 12V, that’s all.

 

@repp089 here is your chance
OEM LED headlight conversion harness for SR/SR5 | Tacoma World

 

Was curious in reading up on these adapter harnesses wondering how Toyota handled 5 input circuits with fuses summing to 20+ amps to a single common ground return. On the factory LED harness, is the common ground wire a larger diameter / lower guage than the inputs or does the LED driver internal to the headlight assembly have overcurrent protection?

 

H9 is spec'd at 65W. Per @crashnburn80's testing, the OEM LED uses 35W (purely off memory, you may wish to fact check me on that?) at full blast. I think we assume high beam draw exceeds low beam which exceeds DRL?

But to your specific point of separate fuses summing up to more than a single 20 gauge wire can provide, I too am curious. I haven't been under the hood of a truck with factory LED headlights yet. Johnny, have you?

 

Glad that made sense, I was thinking out loud there a bit. So H9 is spec'd at 65W, from what I could find the design spec current is 5.4A. The OEM LED pull down roughly 4.5A in total. Normally perfectly fine, and it makes sense for these adapter harnesses to pull a single ground from the H9 connector that can handle 5.4A. It occurred to me though, that H9 ground wire is only sized for a 10A fused circuit. With the OEM LED on high, there would be 20A (10A from high circuit, 10A from low circuit) of fused input lined up on that single ground wire sized for a 10A fuse - fuses being protection for the wires. The Toyota wiring diagrams don't have wire gauges unfortunately. Knowing nothing about the LED driver, I would think the driver would have some type of overcurrent protection, or the factory LED wire harness ground wire is sized for 20A of fuse protection. That assumes the LED driver can even fail in a manner to short all inputs to ground.

So yeah, just thinking (over thinking?) if these single ground wire adapters harnesses have the potential to overheat the factory harness if the LED driver internally shorted.

 

It would be a good question for someone in the biz like diode dynamics’ Paul to comment on. I thought failure for LED is open circuit but the driver may be a totally different story.

I do see the question you pose. And I definitely am curious if the OEM harness for LED is 18 or 20 gauge.