Acura CL Footwell Accent Lighting: Wiring LED Tubes to Switch With Your Interior Lights
Introduction
This guide covers adding LED accent tubes to the driver and passenger footwells of a first-generation Acura CL and wiring them so they turn on automatically with the car's lighting rather than from a plug in the cigarette lighter. You choose one of two behaviours: tie the tubes to the head unit's dimmer-controlled illumination feed so they glow whenever your parking lights, headlights and dash lighting are on, or tie them to the dome-light circuit so they act like factory courtesy lamps that come on as you open a door. The wiring is simple 12 V accessory work and the same approach carries over to other lights in the cabin. The parts are inexpensive, and the discussion covers cheaper tube options, a manual kill switch, and the grounding mistakes that most often stop these installs from working on the first try. Adapted from a community writeup by 97BlackAckCL on AcuraZine (https://acurazine.com/forums/1g-cl-diy-faq-74/diy-footwell-lighting-hardwired-illuminate-interior-lights-489404/), including corrections from the follow-up discussion.
Reference
Tools Required
- Wire strippers
- Electrical tape or crimp/tap connectors (soldering iron optional for cleaner joins)
- 12 V test source (car battery) for polarity checks
- Test light or multimeter to confirm a live feed
- Zip ties (and/or the mounting screws supplied with the tubes)
- Small trim tools to remove the glove box and lower dash panels
Parts Required
-
One pair of 12 V interior tubes: 6 inch LED bars (as used here) or cold cathode computer tubes
-
Optional 20 amp toggle switch for a manual kill switch
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Optional relay and inline fuse if driving a heavier load off the same feed
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Wire connectors, heat shrink or electrical tape
Safety Warnings
- ⚠ Interior neon or LED lighting is illegal to run in some jurisdictions and can earn a citation; an accessible kill switch lets you turn it off when needed.
- ⚠ If you later run a heavier load off the same illumination feed, such as glow gauges, add a relay and an inline fuse; the tubes alone are a light load, but a bigger draw can overload the illumination circuit.
- ⚠ Verify polarity before making permanent connections; reversed wiring or the wrong dome wire can invert the behaviour so the lights come on when the doors close.
Step-by-Step Instructions
1 Choose the tubes and decide how they should switch on
Either interior LED bars or cold cathode tubes work well in the footwells. The original build used 6 inch LED bars with 4 LEDs per tube for a soft glow instead of a harsh light. Before wiring anything, settle on the behaviour you want. Powered from the head-unit illumination feed, the tubes track your headlights and dashboard dimmer and glow whenever the dash is lit. Powered from the dome-light circuit, they behave like factory courtesy lamps, coming on when you open a door and enter.
2 Prepare the tubes and identify polarity
Most 12 V accessory tubes ship with a cigarette-lighter plug; cut it off and set it aside, since the tubes will be hardwired. Strip the two wire pairs that feed the tubes. Briefly touch each pair to a 12 V battery to learn which lead is positive and which is negative, because the tubes only light with correct polarity. On the LED bars used here the silver leads are the ground side. Mark the positive leads so you do not have to guess when you make the final connections.
3 Mount the tubes in the footwells
Place one tube per footwell where it washes light down onto the floor without shining into your eyes. Solid anchor points are the metal support brace behind the glove box and the wiring-harness conduit beneath the steering column. Secure them with the supplied screws, or with zip ties for a hold that stays firm but can be removed later. Loop the ties around the bulb section inside the end caps for extra grip, and stop tightening before the housing starts to flex, because an over-tightened tie will crack the tube.
4 Route the wiring to a switched power source
Run the positive and negative leads from each tube back toward the centre of the dash, where a switched supply is easy to reach. The tidiest tap point is the head unit's wiring, which already carries a dimmer-controlled illumination signal and a good chassis ground close by. Keep the runs neat and leave a little slack so panels can still be removed for service.
5 Option A: Tap the head-unit illumination wire (lights follow the headlights)
On a typical Honda/Acura stereo harness adapter the dimmer illumination lead is orange, and most aftermarket head units, including the Pioneer used here, use orange for the same signal. Splice the tube positives into that orange illumination lead and join the tube grounds to the head unit's black ground wire. Wired this way, the footwell tubes switch on together with your parking lights, headlights and the rest of the dash illumination.
6 Option B: Tap the dome-light circuit (lights follow the doors)
To make the tubes behave like courtesy lamps that switch with the doors, tap the dome-light circuit instead. The security control box sits under the front passenger seat; the feed you want is the light-blue wire on its A connector. The A connector carries fewer pins than the neighbouring B connector, which is the quickest way to tell the two apart. This wire was documented on a 98 2.3 CL and confirmed working on a 97 3.0 CL, so it is consistent across the generation.
7 Ground properly and test before closing up
A bad ground is the single most common reason these installs fail. If a tube lights when touched to the battery but stays dark once connected in the car, move the ground: several builders only got theirs working after grounding to the head unit's own ground wire rather than to a random chassis bolt or the circuit's negative lead. Then confirm the tubes switch with the source you chose. If they come on when the doors close rather than open, you have tapped the wrong dome wire or reversed polarity, so recheck the connection.
8 Add an inline kill switch (recommended)
Because visible interior lighting can draw unwanted attention, and one owner reported being ticketed for it, fit a switch so you can shut the tubes off on demand. A 20 amp toggle switch is more than adequate. Wire it inline on the positive side between the power tap and the tubes, and ground the switch if your setup calls for it. Hide it out of sight but within easy reach, such as a blank switch position, the console, or a cup holder.
9 Aim the tubes and reassemble
With everything tested, angle each tube to spread light evenly across the footwell without throwing glare toward the driver; the zip-tie mounts make these small adjustments easy. Reinstall the glove box, the lower dash trim and any kick panels you removed, keeping the wiring clear of the pedals and any moving parts.
Pro Tips
- 💡 Cold cathode computer tubes are a cheap alternative, around $6 for two 12 inch tubes on eBay; loose LEDs wired in are cheaper still.
- 💡 Zip-tie mounts let you pull and re-aim the tubes easily; snug the ties around the bulb ends inside the mounts for a better hold.
- 💡 The head-unit illumination tap makes the lights follow your headlights and dimmer; the dome-circuit tap makes them behave like factory courtesy lighting.
- 💡 To identify the security box under the passenger seat, remember the A connector has fewer pins than the B connector.
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