DIY Amber City Lights in Honda Headlight Housings
Introduction
City lights are the small amber or white marker lamps that glow inside a headlight housing, a look normally associated with JDM assemblies. Rather than buying a second set of headlights just for that feature, this guide shows how to graft an extra bulb socket into a standard USDM housing so a low-wattage bulb shines from within the reflector. The socket is salvaged from a common automotive side marker, mounted through the housing with a rotary tool, sealed against moisture, and wired to its own switch. The technique suits Honda Civic (EG) and CR-X del Sol headlights and adapts to most other Honda housings with room behind the reflector. Adapted from a community writeup by SMOOTHN on Honda-Tech (https://honda-tech.com/forums/lighting-107/smoothns-diy-city-lights-2163034/), including corrections from the follow-up discussion.
Reference
Tools Required
- Rotary tool (e.g. Dremel) with cutting and grinding bits
- Heavy-duty shears or similar cutting tool
- Sandpaper or a sanding bit
- Basic wiring tools (crimps, connectors, or solder)
- Shop rags and clean water for rinsing the housing
Parts Required
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USDM headlight housings
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Donor automotive side markers for the bulb sockets (junkyard Saab units work well)
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194 wedge bulbs, or LED wedge bulbs for lower current draw
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Seal-All or silicone sealant
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Rubber grommets (optional alternative moisture seal)
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Wire and inline connectors for the added circuit
Safety Warnings
- ⚠ OEM fluted or faceted lenses combined with a plug-and-play HID kit can throw heavy glare toward oncoming traffic; aim carefully and use responsibly.
- ⚠ Always rinse every trace of drilling debris from inside the housing before sealing, or loose plastic can block the reflector.
- ⚠ Running a small 194 bulb at the same time as bright HIDs adds heat and can shorten the little bulb's life; giving the city lights their own switch avoids that.
Step-by-Step Instructions
1 Gather parts and choose donor sockets
Collect the USDM headlight housings and a pair of side markers to donate their bulb sockets. Junkyard Saab side markers are a good source because their sockets accept a standard 194 wedge bulb. Have the rotary tool, shears, sandpaper, sealant, and wiring supplies on hand before you begin so the build runs without interruption.
2 Free the socket from the donor marker
Cut away the lens and outer body of the side marker with the shears, keeping only the bulb socket and a short collar of surrounding plastic. That collar becomes the anchor that later holds the socket in the headlight housing, so leave enough material to work with.
3 Slim down and shape the socket mount
Sand the salvaged collar until its bulky edges become a slim, even profile that will seat flush against the housing. As an optional refinement, shorten the socket barrel so the bulb sits deeper inside the reflector; this pushes more of its light into the lens. Compare bulb depth before and after trimming to confirm the improvement.
4 Open the mounting hole in the housing
Pick a spot on the headlight housing with clearance behind the reflector, then use the rotary tool to bore an opening matched to the trimmed socket. Enlarge the hole a little at a time and test the fit often, stopping once the socket presses in snugly without slop.
5 Rinse plastic debris from the housing
Boring the hole scatters melted and cut plastic inside the reflector. Flush the interior with clean water and dry it fully so no fragments remain to rattle loose or cast shadows across the beam.
6 Dry-fit the socket before sealing
Set the socket into its opening and check that it sits square and the collar makes even contact all around. Correct any high spots with a little more sanding now, while the joint is still easy to adjust.
7 Bond and waterproof the socket
Fix the socket permanently and seal out moisture with Seal-All or silicone worked around the collar. A rubber grommet with a hole sized for the socket is an alternative that both locates and seals the part. Let the sealant cure completely before handling the housing further.
8 Fit the bulb
Push a 194 wedge bulb into the socket for a simple amber glow, or use an LED wedge to reduce current draw. If an LED's beam is too narrow and spot-like, clip the tip off its lens so the light disperses more evenly inside the housing.
9 Wire the city lights to a switch
Run a feed to the new bulbs from a circuit you can control independently. Because the low beams here use a plug-and-play HID kit, the city lights were tied to the high-beam switch, letting them come on with the parking lights while keeping them off whenever the HIDs are lit. Splice cleanly and protect the added wiring.
Pro Tips
- 💡 LED wedge bulbs draw very little current, so they can be left on without noticeably straining the battery.
- 💡 To widen a narrow LED beam, cut the tip off the LED lens; it took the author about a week of experimenting to learn the basics of working with LEDs.
- 💡 A rubber grommet with a drilled hole is a clean alternative to sealant for keeping the socket watertight.
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