After going through several different types of direct plug in LED 3157 bulbs, I got fed up with the sub-par light output and reliability… Seemed like they either didn’t have much brightness difference between running lights and brake/turn signals, or they didn’t last more than a month before they started flickering or having individual LED’s start to die. Working in a junk yard, I noticed some interesting looking LED’s in the taillights of some newer body style Ford Mustangs, Chevy Impalas, and Mercury Mountaineers, and I don’t know why it took me so long to try to retrofit these into my taillights…

The LED’s I’m referring to are Osram Joule LED modules. The key to the brightness in these is the way they reflect the light output back to the reflector in the taillight so the light is actually aimed back from the vehicle by the taillight itself, not just out in the open LED’s throwing unfocused light all over the place like the majority of 3157 direct plug in LED bulbs. The base is also made of aluminum and acts as a built in heat sink, so that probably helps with the life of the bulb.

I have these installed into my aftermarket taillights and the light output is AMAZING! Right now to installed them, I took some original 3157 sockets and hacked them up, gutted and trimmed them, slipped them over the Joule LED after trimming off its factory locking tabs, and epoxied them together. Doing this lets me reuse the 3157 rubber gasket so there’s no moister issues to worry about, and after clocking them correctly (which is VERY important to getting these to fit), they turn and lock into the taillights like a stock bulb. I have another set of bulbs and some broken taillights that these originally came in, and my plan in the future is to actually cut out the bulb mounting flange from the taillights and epoxy those to my taillights directly, so that the Joule LED bulb will lock into the taillight without being modified, convenient if I ever need to replace one since it’ll be a plug and play (right now I’d have to remake a new bulb if one were to burn out…)


This was the plug in 3157 LED’s that I had to start with (picture was originally taken showing the reverse light bulbs, but you can see the LED’s in there)





This is the Joule LED (after I cut off the original locking tabs on it, prepping to epoxy the 3157 adapter ring I made onto it)





Here’s one of the adapter rings I made from a factory 3157 socket





Mocking up on the bulb. Notice the black alignment mark. To clock them into the right position, I just put the ring into the taillight and turned it and locked it into place, then placed the Joule LED into the ring and turn it until it lined up where I wanted it. Then I could press onto the bulb with a little more force and the Joule LED would grab the ring good enough just by shear friction so that I could turn it and it would unlock the ring from the taillight and I pulled them out together, then marked where they needed to be lined up. Basically just lining up the plugs so they'll all fit in the taillight pocket.







And epoxied into place.







Then I just had to cut the original harness up and splice in the new plugs that plug into the Joule bulbs.





One in, just had to test





Plugs spliced in and wiring cleaned up.




And here’s the back side with the bulbs installed and all plugged in. It’s a VERY tight fit, but everything clears great and the taillight goes into place with no resistance.





And like I mentioned, light output is AWESOME!









This is not the easiest LED taillight setup by any means, neither is it the most difficult, but in my opinion, it’s probably one of the best as far as light output performance and reliability since it’s basically using OEM components (minus the taillights themselves of course). I would be curious to see how these would perform in a factory taillight, but I like my aftermarkets

 

Nice work!

 

Thank you

I would also suggest to anyone attempting to do this, SOLDER your new plugs on, do not use crimp connectors... Space is tight behind the taillight, and 6 crimp connectors are going to be bulky and make for a tight squeeze. Plus, crimps can be rather unreliable, and the last thing you need to have happen is a wire to vibrate loose from the connection and for you to loose brake lights or running lights... Soldering them takes up FAR less space and makes the wire management easier and cleaner, and is also a more reliable of a connection

 

Nice, those look sweet, and look to be far easier than a full retrofit.

 

Little more insight into this mod, and these LED's

Brought home some "spare" Joule modules from work, as well as some busted tail lights from a Ford Mustang that come factory with these modules, so that I can dremel out the locking hole area that the bulb goes into and glue that piece to my tail lights to make for a better mounting solution. I'm going to use two of the bulbs to retrofit my fiance's 2010 Hyundai Elantra too, so I'll probably use the hacked up tail light mounts for it, since mine are already functional as-is.







So far I've found 3 different variations of these bulbs/modules.







There's the ones that I used, came from the Ford Mustang tail lights. Use the standard 3 wire connections (ground, running, and turn/brake). Part number L1230R-3N.









There's ones in some Mercury Mountaineers, seem to be the same other than the clear light tube being physically shorter for a different focus length. Other than that, they use the same plug and all. Part number on those is L1224R.









Then there's the ones that GM uses in the Impala LTZ's. Same physical dimensions as the ones I used from a Ford Mustang, but they use a 4 wire plug. From playing around with them, two appear to function as a ground, while the other two are the running and turn/stop signal wires. Part number on those is L1230R (almost the same as the ones in the Mustang, so be careful if trying to order them, make sure you get the one you're actually after, the 3 or 4 wire one).









Also, I just so happen to find the video I made after completing one side lol. I knew that I took a video and I copied all the pictures and video from my phone over to my external hard drive not long after, but couldn't remember where I put the video :P

 

Threw some in the fiancé's 2010 Hyundai Elantra this morning. Just one bulb per light, so half the work I guess lol. Had to get a little more creative with the bulb mounting, space is REALLY tight in it... but, at least I don't have to worry about moisture problems in it since it's a sealed into the trunk system. Wiring was a breeze, 3 wires per bulb, replacing a dual filament bulb, just like on the Blazer. Came out great and they're BRIGHT!