There are a lot of threads about problems people encountered when trying to replace their lights (mostly the turn signals / flashers causing problems) with LEDs. I figured I would document my replacement effort in the hopes it helps someone else going forward.
Tools and equipment: LED light kit (obviously), flat head, Philips screwdriver, wire strippers, crimpers, heat shrink seal, dielectric grease, silicone, power drill + suitable bit.
I bought a set of 733 MM LED Style Wipac lights for the brakes, signals, and parking lights. Part # DA1192 and it ran me $184 on EBay and came with a working signal relay.
I bought 7" round LED headlights from SuiTech on Amazon but wiring for many comparable lights will be similar. Choose ones you like. Mine cost about $185.
1) Take a small flat head screwdriver and pop off the old / existing plastic covers for the turn signals and brake lights in the rear. Repeat the same in the front. Mine were a bit stuck but there is a small slot at the bottom of each that gave me room for a small flathead. I wasnít too worried about cracking the plastic since I was looking to replace the set, but everything came off without issue.
2) Unscrew the retaining plates / mount for all lights. Itís ok to let the lights hang from the cords at this point. There should be ample slack to work with unless someone has already cut into your wires during a previous mod.
3) This might differ if you have a newer truck but my existing brake and turn lights did not have plugs. They were wired as a unit so I had to cut and splice. Maybe you will be lucky and have a plug but if not, making new connections is not hard. I just cut off the factory plugs.
4) I recommend a little Dielectric grease on each of the connections if you use terminals. This will help prevent corrosion. You can get it at Home Depot, Amazon, or most Auto Stores.
5) I started with the turn signal since there are only 2 wires (live and ground). Splice the wires together and test that it flashes (donít worry about the flash rate for now). If it does not work then try grounding directly to a valid ground on the chassis. I found that the LEDs are more picky about a good ground than the old bulbs which seem to be able to ground through one another to a common ground.
6) Same idea with the brake lights but there are 3 wires. One is ground, one is the rear running lights that go on with your headlights, and the final is the brake light. Youíll need a friend to test the brake for you since you canít readily see the rear while applying the brake (maybe you can back up to a wall if you have no friends to help). Your colors may differ but there doesnít seem to be any harm to guessing wrong a time or two. Just keep the connection quick release or hand wrapped until you get it right. I finalized all my connections with crush connectors and marine rated heat shrink (available on Amazon).
7) Up front the turn signals are the same as the rear, and the white parking lights are also simple two wires.
8) You need to remove the front turn signals and parking lights as well as the 2 retaining screws in the plastic light surround to access the headlight harness.
9) Before you do the headlights you might want to check the level of the existing lights. Park about 25 ft from a wall and use painters tape to mark the brightest point / center of each headlamp. This way when you install the new lights you can line up the new bright points with the old ones.
10) Once you remove the surround you will find a few retaining screws holding the headlight in place. Note that the screws at 9pm and 12pm position are leveling screws used to align the light once re-installed. You may want to loosen these to ease the removal of the headlamp but you donít need to take them all the way out.
11) Once you remove the headlight you need to remove the chrome harness. Mine was a tad corroded so I hit it with some steel wool / polish and shined it up. Make sure you donít lose the retaining clips and screws for the harness since it will be needed on the new light as well.
12) Here I was pleased/surprised that I DID have a plug and it worked with the pins/plugs for the new headlight. Iím not going to get into wiring the halo light in this post. Only focused on low and high beams for now.
13) Once you confirm the headlights work for low and high beam, reverse what you did to take out the headlights to reinstall them. You can level/align them to your preferences / legal requirements.
14) Now go to the fuse panel in front of the shifter and remove the knobs to release the retaining plate.
15) Find the flasher relay (black box, mine was wired with a metal clip and ground to the retaining plate.
16) Replace the relay with the one from Wipac or whomever makes your light. They sell them on Ebay for $10 if your kit did not come with one. You will need this relay or the flash rate wonít be right/legal. You can install resistors instead but this is silly since it increases the power demand of the lights and LEDs are appealing in part because they are so energy efficient. You could probably get away with leaving the parking lights all night and not kill your battery with LEDs (I do not endorse this, just saying).
17) Now, go check all your lights to see whatís working. If you did the wiring correctly then the brake lights should be fine, headlights too. I ran into problems with my turn signal. This is a well documented issue with some Defenders but I had to search around a few forums to find solutions. Basically there is a tell tale / indicator bulb in the dash panel (the <-- --> green light that flashes when you use your signals). Some current leaks through the bulb and with the low power demand of the LED is lights up the other side (the current leaks with the incandescent bulbs too but you wonít get enough to light up). If you remove this bulb it will fix the turn signals. But it means your flashers donít work. I believe this means you fail an MOT but will probably pass a U.S. state or city inspection (not encouraging this, just being realistic about the depth of checks I generally see when I get a vehicle inspected). Iíve been in touch with boltonbits (UK) via their EBay store. They have an ďLED indicator fix kitĒ for 15 GBP delivered in the UK mainland (more for shipping stateside). Thereís also an option to solder in some diodes to prevent the current leak behind the tell tale bulbÖdepends on your wiring savvy.
18) If someone comes up with another solution for the indicator light / flashers Iíd love to hear it!
19) Assuming you are happy with your wiring then itís time to mount the new lights. Maybe you will get lucky and the new lights will have holes that match the old. Mine did not. I took painters tape and placed it on my car to protect the paint. Then I put the new light in place, and used a pencil to make the location of the holes.
20) Double and triple check the size of your bit vs the screws. I used some scrap metal for testing. I drilled right through the painters tape to prevent flaking of my Defender paint and ensure I drilled the right spots. Rinse and repeat until all the holes are set.
21) Use some kind of anti-corrosion agent on the holes, both old and new. I also applied a bit of silicon to mine since the spray from the tires will otherwise blast the back of the light and make it all gross over time. I have a black truck so I bought black silicone. You wonít see it anyway but Iím picky.
22) Reinstall all the lights by tucking the wires in place and screwing the retaining bolts/screws in place. Test the lights once more.
23) Enjoy! Now people can actually see you and you can see the road (if not your instrument panel but thatís another thread).