DIY Octavia 2 front footwell lighting

[sebulbus]

I saw this in other cars, so I decided I absolutely must have them. However, I didn't want any wires to be visible, and for the most part I wanted to have the LEDs out of sight too.

I decided I needed white light that went on whenever the main dome light was on, either with a door open, car unlocked, dome light turned on, etc.

Here is a walkthrough on how to install these in a mk2 Octi, but this can be expanded to other cars, improvising as needed.

Keep in mind that it is an LHD car, so mirror the instructions to install on your RHD car.

What you need:
- LED modules. I bought modules that had the 3 superbright white diodes and the current limiting resistor and connections enclosed in a clear plastic body. Whatever you pick, make sure it's a wide beam pattern (mine are 120 degrees) so you have a nice even light in the entire footwell.
- Power cord. You need any kind that has 2 conductors in a single jacket, not too thick or stiff since it's not passing any real current, plus you have to snake the wires behind the panels.
- Heatshrink wire wrap. Lots of it, different diameters.
- Electrical tape. Useful as extra insulation, and more.
- Inline splice connectors, soldering iron plus all the extras, a #2 Philips screwdriver, preferably magnetic. A voltmeter is useful.

What can go wrong:
You will have to solder 2 wires to the front dome light to power the footwells from. It's easy, but if you have absolutely no practice or talent for it you might melt some of the plastic around there. It's obscured from view, though.
There is also a chance that you might touch metal against the metal traces in the dome light, thus burning the fuse.

Actual procedure:

1. The dome light.

Take the front dome light off. You do that by removing the plastic difuser covering the bulbs, pry the edge closest to the windshield out first with a coin, and it will unclip exposing the bulbs.
Then take the #2 Philips and unscrew the two screws located to either side of the middle bulb. If you are not using a magnetic screwdriver just remember to cup your hand around it, or dear old gravity will make sure the screw goes somewhere you will have a hard time reaching.
After removing (and saving) the screws return to your trusty coin. Pry out either edge of the dome light and it will fall straight down, dangling on it's power cord.
Disconnect it by pulling and wigling the connector, it will give eventually. Watch the knuckles, the liner cutout has metal clips on the edges.

Take a minute to consider what you want to do. Looking at the power connector for the dome light, the middle is a permanent power, well almost. It is switched on when you unlock the car and stays energized for 5 seconds after you lock it. The other two wires are grounds, one coming from the door switches, and one permanent for when you operate the light via the switch.

If you want lights that stay on constantly you can just tap the middle wire and ground to the exposed metal body. However, I needed the footwell to stay lit whenever the dome light was one, either via switch or door open, etc.

Right, back to the tutorial. Take your dome light inside, and place it face down on a soft cloth, or anything that won't damage the finish.
Follow the middle bulb's contacts to a convenient place to solder two wires. I chose the spot to one side of the bulb socket where the traces run side by side.
Cut a 7-10" section of wire, strip and tin the wires at one end. Crimp inline splice connectors to the other end and heatshrink the crimped ends of the connectors. Pull on them to make sure the wires are properly secured and won't come off. Put some heatshrink on the wire for later and don't heat it in place yet.
Returning to the dome light, put some flux on the place where you will solder the wires and heat for a second with the iron. Then take your solder, heat the trace and put on two blobs of solder, and let them cool. If they are not shiny that's called a cold joint and won't conduct electricity properly. Put on more flux, heat the trace properly and add a bit more solder.
Now take your section of cord with the crimp connectors at one end and solder the tinned ends onto the blobs. They should fuse nicely. Remember a good solder joint is shiny.
Next find a spot where you can zip tie the wire to the dome light shell, and move the heatshrink acordingly. Heat it to secure, then fix the cord with the zip tie and clip it.

The dome light is done for the moment. It should look like the attached picture. Excuse the poor quality, a Nokia E50 was all I had handy at the moment.

[sebulbus]

2. Preparing the LEDs

My LED sticks were simple blocks with bare wires at one end, we will asume yours are the same, or you can adapt as needed.

Take the LED sticks and strip the ends of the wires. Put a bit of solder flux on, heat it, then tin the ends. Cut two pieces of heat shrink and put it on either wire. Then a larger diameter piece covering both.

Take the cord that you will be using, cut aprox 6 feet and strip the wires at one end. Flux and tin these as well. Put a couple of inches of heatshrink on the cord jacket and slide it away a bit.
Now it's time to solder each wire and pull the heat shrink over it. Don't take too long or the radiated heat will fix the heatshrink in place away from the solder. If that happens, start over. Next pull the bit covering both wires over the soldered wires and heat it. Let it cool then pull the heatshrink from the cord until it touches the side of the LED stick. Heat it as well.
Moving to the other end of the cord,strip 1" of jacket, then strip both wires, flux and tin. Secure both wires together with a bit of heatshrink, then pull on more heatshrink to hold the outer cord jacket and wires snuggly.
Fix double sided tape to the back of the LED sticks and cut it to shape. I use Bison Auto tape which does a great job keeping things put even at -20 C or below.

You should end up with something similar to what I have in the pics below. If your interior is beige buy beige cord and heatshrink to keep things neat.

You can see my LED sticks had wires at both ends. I clipped one end flush and covered the end with nail polish, which is a good enough insulator. 2 coats were enough.

[sebulbus]

Back to the car now, connect the dome light to it's connector and double check with your voltmeter which wire is the ground. Commit to memory.

Open the driver's door, remove the side cover by the fuse box (there is a recess big enough to fit the key) and set aside. Putting one hand behind the fuse box (hope you have small hands, or else) and sliding a finger from under the dash, where two pieces of plastic trim overlap you can get an idea of where you can snake the wire through.
Guide the LED stick through there, or use a guide wire, then stuff the cord in the seam where the trims overlap, right in front of the footwell vents, until your stick reaches the center of the footwell. Hide the wire properly and don't stick the LED strips for now.
Don't run the cord close to anything moving (steering column or pedals), please.
Returning to the other end of the cord, pull the wire between the side of the dash and the door seal, then up between the side of the dash and the A pillar, towards the windshield. Stuff it deeper down with an old credit card, hard piece of cardboard, trim removal tool. Anything works, really.
Now run the wire up the A pillar, between the windshield and the trim cover. I must stress that you take this route, no variations if you have curtain airbags, like I do too. If the wire is to thin to stay put just roll some electrical tape on it sticky side up and it will hold.
At the top, push the cord behind the headliner, pulling it down a bit to make it easier, then when you get to the rearview mirror mount push it inside and fish it out from the dome light opening. This is also a place to use a guide wire if you have large hands.
Tie a knot in the wire and fix it with the sun visor for now, then repeat for the passenger part passing the wire through the side dash cover and behind the glovebox, fishing it from below. It's a lot easier on this side.

I don't have any pics of this and the next step, but you should get along fine with the instructions.

[sebulbus]

With both sides' wires hanging from the dome light cavity test each by touching to the inside of the crimped connectors to make sure they still work. Having 3 hands is useful here.

Assuming everything is ok, take both cord, put a piece of heatshrink over both about 2-3" from the end, heat it, then fix them with a zip tie and clip it. Next secure both ground wires together in heatshrink, twist the wires together and heat them a bit, which should make the solder melt and fuse them together.
Stick them in the crimp connector and crimp. Pull and wiggle to make sure it stays put.
If everything's well, cover the connector and wires to each side in electrical tape.
Repeat for the other lead, then secure both together with electrical tape, zip ties, etc.

Test one more time.

If everything works properly, tuck the wires inside the headliner, refit the dome light (take care not to lose the screws) and you're done.


Ta daa.

[sebulbus]

Pictures of the job completed. The much whiter LEDs make the dome lights appear yellow. I am considering changing the bulbs to match colours.

[yashicamat]

Excellent guide.

I'd definately do this if I thought I was keeping my car longer than another 6 months.

[sebulbus]

I'm very picky about everything, and one of the most important aspects was that it should look OEM.
You can probably take shortcuts on most steps, I like to be extra cautious.

[smstext]

nice one. just an idea but if you connected the wire to the internal light fuse would it be easier than connecting to the dome light???

[sebulbus]

You'dd only get footwell lights that are on for the entire time the car is unlocked.
You need to tap at the dome light, since the dome light is powered from 2 independent sources.
One is the interior lights dimmer, which turns it on whenever any of the doors is open, when you unlock and when you take the key out of the ignition. The other is the light switch, which turns it on directly, bypassing the dimmer circuit.
No worries, soldering two wires onto the back of the dome light is not at hard as it sounds. The traces are wide enough to not short anything together, and you'll probably have it done in < 5 mins.
I'm thinking of also doing this mod for the rear, but I don't want to route the wires past the rear curtain airbags, so they'll have to be coming in from the front as well, then routed towards the back under the door sill trims.

[simonlb]

I'll just add that this modification to the dome light allows you to splice in rear interior lights if you don't have them.
Last year I fitted a pair I got from a Ford Galaxy and ran the cables to the light but wasn't sure how to connect them up so I left them disconnected - this guide was ideal and after soldering the feed and earth as per the pictur, I now have working rear interior lights. Excellent!!