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DIY: OEM LED 3rd Brake Light Conversion

20091 Views 30 Replies 13 Participants Last post by  DeSEBticoN
These is the 3rd brake light we should have had. At least in the 2nd gens. So many other manufactures have LED 3rd brake lights, it's baffling why we didn't get one.


I wanted a full LED brake light setup for safety purposes and to look cool (duh). After going with Philips Vision LEDs for the main brake lights, I also tried their 7440 LED for the third (high-mount) brake light because all quality LEDs were too long. However, output was fairly dismal compared to stock during the day. I considered VLED V3 Tritons since the LED can be adjusted shallower. But I didn't want the fairly long and expensive Triton hanging down into my trunk space where I often throw in duffel bags and such. I then read that some Civic and Accord folks were swapping out their stock third brake light housing for the OEM LED one found in 2010+ Civic Hybrid models. Couldn't find any TSX owners who had done this so I documented the process so others may do what I did.

Parts needed:

1x 34270-SNC-A02 - High Mount Lamp
~$100, found here or the parts site of your choosing: HIGH MOUNT LAMP | Genuine Honda | 34270-SNC-A02
Note, make sure it's the "A02" and not the "A01", which is the older design with much more separation between the dots.

1x long skinny screwdriver

2-4x zipties
Depends on length but I used 3 because of the length.

1x needle-nosed pliers


1. Remove the bulb from the housing.

Inside the trunk, remove the bulb from the third brake light housing by rotating the connector counter clockwise.

2. Test the new housing.

Make sure it works before doing all this. Unclip the OEM harness from the bulb connector and plug it into the LED housing. Either have someone press on the brake pedal or do what did and stick something between the pedal and the seat. I used a short-ish umbrella. If it lights up, proceed!

3. Prepare the removal of the third brake light assembly from the top of the back seat.

This is easier than it seems. Inside the trunk, where the green circles are, you should see red and silver tabs in each area. Stick the screwdriver in and move/push the tabs kind of into the holes. There are 2 total.

By this point, the assembly should feel lose.

4. Remove the assembly.

Inside the cabin, behind the backseat, use your fingers to pry up the assembly. May take some finesse. It can be tight but it can come out.

5. Remove the stock bulb housing from the outer cover.

It's simply a process of popping out the tabs of the housing from the cover.

6. Install the new OEM LED housing onto the stock cover.

Comparing the two housings and the location of the tabs, you can see that the new housing will fit right in where the old one was.

If you look closely, you can see that some things are missing on the new housing. Namely, the silver tabs on the old housing, not circled. Those tabs are what you pushed back from inside the trunk with the screw driver. They are very important and they secure the housing down to the top of the trunk. It should be mentioned that when I was doing this, I didn't notice the new housing didn't have those tabs until I put in place on top of the trunk. The whole thing was very loose and insecure.

I considered superglue. Nah. I tried 3M double-sided tape (the gray stuff). Wasn't secure enough and looked weird. Good old zip-ties seemed like a good solution.

Piece together the zipties and put them between the cover and the new housing like so:

7. Install the new housing.

This part is a little tricky. From inside the cabin, while making sure the zip-ties are still on top of the LED housing, eventually "pulling down" on the housing to keep it in place, feed them through the holes that the silver tabs were in. See the picture in Step 3 for reference. I may have used the needle-nosed pliers at this point to grab them from inside the trunk. Pull the zip-ties through from inside the trunk and ensure the assembly itself is laying flat like the stock setup did from inside the cabin.

8. Secure the housing in place.

Connect the zip-ties together and tighten, but not over-tighten. Just until the assembly from inside of the cabin doesn't budge and the cover has very little if any gaps in the cabin.

9. Connect power to the housing.

Connect the plug from the stock harness into the LED housing again and you're in business!

A white/clear third brake light when off and when on you get OEM brightness and quality that performs better than any aftermarket LED.


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Very happy I found this thread. Just installed a used 2006 LED CHML I found on ebay for $35. Your instructions were great and it looks and functions like OEM. Thanks!
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