Installing an LED Daytime Running Light (DRL) Kit and Control Module on a Honda Civic
Introduction
This guide covers fitting an Atomic LED daytime running light (DRL) kit and its control module to a Honda Civic. The kit mounts a pair of low-draw LED strips to the front grille (or, in the alternate version, into the fog-lamp blanks); they light automatically once the engine is running and switch off when the sidelights come on, keeping the setup road-legal after dark. The control module removes the need to hunt for a switched ignition feed and to run a manual switch back into the cabin: it senses the rise in battery current the moment the engine starts and powers the LEDs from that, then cuts them through a single sidelight tap. Fitment is broadly the same across Civic variants, but battery position differs between petrol and diesel cars and can leave very little working room behind one headlight. Adapted from a community writeup by atomic on Civinfo (https://www.civinfo.com/threads/how-to-fit-atomics-led-drl-kit-control-module.60966/), including corrections from the follow-up discussion.
Reference
Tools Required
- 2mm Allen key
- Spanner/wrench to match the mounting nut
- Drill with a 1.5mm bit
- Pliers
- Sockets and screwdrivers for front bumper removal
Parts Required
-
Atomic LED DRL kit (two LED units plus control module)
-
Red Snap Clip (scotch-lock) connector for the sidelight tap
-
Double-sided foam tape to mount the control module
Safety Warnings
- ⚠ Never disconnect or reconnect the battery with the key in the ignition. Doing so can wipe the immobiliser and leave the car unable to start.
- ⚠ Route all wiring well away from the radiator and coolant pipes, which get hot enough to damage insulation.
- ⚠ Leaving the DRLs on at night alongside the main lights can dazzle oncoming drivers and may be illegal; wire them to switch off when the main lights come on.
Step-by-Step Instructions
1 Remove the front bumper
Take the front bumper off to reach the back of the grille and the area beneath the headlight units. Use the same removal procedure the platform uses for fitting fog lights. With the bumper away, the grille mounting points are exposed and you can route wiring up from below the headlights.
2 Mount the LED units to the grille
Prepare each mounting bolt by running its nut fully up to the bolt head, holding the bolt with a 2mm Allen key and turning the nut with a spanner. Pass the bolts through the mounting bracket that sits behind the grille and thread them into the LED units on the front face of the grille. Press each unit against the grille and wind the nut back down the bolt until the unit is clamped firmly against it. On the fog-blank version of the kit the bracket is not used at all: the LED units simply clip into the fog blanks.
3 Route the harness through the engine bay
Feed the module's red and black leads, which terminate in bullet connectors, forward through the engine bay and bring them out from under the headlight units. Keep every run clear of the radiator and coolant pipes, which reach high enough temperatures to melt insulation. Bring the LED unit leads to meet the module in the same area near the battery.
4 Isolate the battery
Make sure the ignition key is out of the barrel, then disconnect the battery before making any power connections. Handling the terminals with the key in place risks disturbing the immobiliser, so confirm the key is removed first.
5 Connect the module power leads
Attach the module's red lead to the battery positive terminal and the black lead to the negative terminal or a solid earth/ground bolt on the body. Keep both joints tidy and close to the battery so the finished wiring stays neat rather than trailing across the bay.
6 Join the LED units to the module
Mate the bullet connectors from the two LED units to the matching connectors coming from the control module. The connectors are keyed to their pairs, so each LED unit links to its own lead from the module.
7 Test daytime operation
Reconnect the battery, start the engine, and confirm that both LED units come on. This checks the power side of the install before you move on to the sidelight signal wiring. Switch the engine off again before continuing.
8 Open the light cap and pass the orange wire through
Open the cap on the right-hand light unit and drill a 1.5mm hole through it. Thread the module's orange signal wire through this hole so it can reach the sidelight wiring behind the cap. Take care not to enlarge the hole beyond what the wire needs.
9 Splice the orange wire into the sidelight feed
Join the orange wire to the sidelight wire with the supplied Red Snap Clip. Seat both wires in the clip, then press the metal bridge down with pliers until its locking tab folds over and clicks home. Confirm you have tapped the sidelight wire and not the main-beam wire: connecting to the wrong circuit leaves the DRLs lit until high beam is selected. The sidelight wire colour varies between cars, so verify the circuit before you cut into it; it is often white but can be grey, and on some cars white feeds the main beam instead.
10 Mount the control module
Fix the control module near the battery. A strip of double-sided foam number-plate tape on the side of the battery tray holds it securely. On petrol cars the battery sits further forward and can leave only about a hand's width behind the passenger-side light, so keep the module and all connections at the battery end where there is room.
11 Confirm night cutoff and reassemble
Refit the light cap without pinching any wires, switch on the sidelights, and confirm both LED units go out. If they stay on or dim unevenly, check that the snap clip is fully compressed with no metal protruding; swapping the two LED units left to right has also cleared dimming faults for some fitters. Once operation is confirmed, refit the front bumper.
Pro Tips
- 💡 The alternate fog-blank version skips the grille bracket entirely: the LED units clip straight into the fog blanks and use the same bullet connectors as the grille kit.
- 💡 A brief flash of the DRLs when you lock the car is normal. The module reads the momentary current draw as an engine start; the tiny LED load will not drain the battery any faster than locking it normally.
- 💡 To make the DRLs switch off with the headlights or HIDs instead of the sidelights, tap the orange wire into the headlight positive feed. The installer's own recommendation, though, is to switch them off with the sidelights.
- 💡 Room behind the passenger-side headlight is tight; removing the light connector makes it easier to seat the snap clip.
- 💡 Keep a spare snap clip handy, as they are easy to drop into the engine bay during fitting.
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