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44 Posts
Discussion Starter #1 (Edited)
Yes...I know the issue of 2008-09 Foci missing rear dome lights from the factory has been addressed already. In fact this thread is inspired largely by DarderSauce’s write-up on how he installed LED stripping along the back window. I liked that idea, but I really like to keep everything looking super OEM. I dug and dug and just could not find the part # for whatever dome light Ford allegedly started installing in the 2010-11 Foci. But when I was perusing Ebay, I discovered a plethora of available dome lights from MK3 Foci, and they look like they juuuust maybe could belong in a Mk2 interior. Here’s what I’m talking about: 2012+ Dome Light

In case y’all don’t know, there were a few different interior lighting configurations available for the MK3, depending on trim level. I looked into the dome lights from the Titanium first, since they have built-in LEDs and buttons to control them. Unfortunately I came to the conclusion that these would not be worth the effort of trying to decode the 6-pin digital connector and wire straight in to my map light.

My attention then turned to the basic dome light from the S/SE models. These have just 4 analog pins (afaik...), no buttons, and come in the same “medium light stone” color as my ‘09 Coupe’s interior. And instead of built-in LEDs, they sport a standard 168/W5W bulb socket, same as the existing map light. I’ve already fitted nice bright 6500K LEDs into my map light and have a few extra lying around, so I’ll be able to match the new light’s color tone to those and have an even more OEM- looking setup.

Anyhow, I snagged a nice-looking example on EBay for $16 and will try and install in the afternoon tomorrow. I’ll post an update when I get it done, and will do my best to take pictures and document the process into a formal write up in case anyone wants to try this themselves!

Cheers till then,


44 Posts
Discussion Starter #2 (Edited)
Install done, it turned out even better than I imagined.

As promised, here's an in-depth how-to with lots of pictures. Hopefully this helps any of you early-MK2 owners who could use a little more light in the back seat or need a fun 2-hour project!

***Disclaimer: I am not liable for any damage to your car or yourself, caused by usage of this guide, or user error. This is only intended as a useful and informative article. Please read this guide all the way through before you start so that you know what you're getting yourself into.

^^ With that said, this is an easy project. The hardest part was trying not to cringe while slicing apart my headliner!



  • Dome light (preferably LED)
  • ~3ft of wire
  • Lead-free solder
  • Roll of paper towels
  • Measuring tape
  • Dull pencil
  • Soldering iron
  • X-Acto Knife with new/sharp blade
  • Scissors or Wire strips
  • Flat blade screwdriver
Step 1: Source a dome light to install

I've read that people have used parts from PT Cruisers and Suzukis in the past, so you really can do whatever you want. Personally I wanted this to be a clean, OEM-looking install so I found one from a 2012 Focus SE Hatch on EBay for $16:


I had already upgraded my existing map lights to LED, and had extra bulbs, so I swapped the stock halogen bulb that came with it for my own LED bulb and cleaned the 'EBay used part' grime off the unit while I had it apart.

(Note: If your map lights are still halogen, I would consider swapping to LED all around, and refrain from adding another halogen bulb to the circuit. LEDs draw far less current than halogens, so this will eliminate the possibility of overloading your circuitry and popping a fuse. )


Step 2: Remove map light

Pop off the opaque plastic bezel with the clear lenses (didn't grab a pic of this, sry), as if you were changing map light bulbs. If you've never done this or it's stuck, practice patience and try using a plastic credit card or something to pry, starting by the lenses. It is pretty intuitive. Once this is off, grab around the tan square plastic piece in the middle and pull down. The inner assembly should gently pop out of the frame holding it in the headliner. Unclip the wiring harness to free it and set aside.


Now unclip the plastic frame that remains in the headliner. It's easiest to use a flat-blade screwdriver to push each of the four corner clips inward so that it can pop out. Remove and set aside. The metal retainer plate that sits in the hole can stay.

Step 3: Locate Map Light wires to tap into

Up-close of wiring clip:


Here's what each wire does:
  • Dark blue wire on the left is +12V
  • Middle gray/purple wire is ground for the dimming/open door circuit
  • Yellow/green wire on the right is solid ground for the map lights.
The reason Ford used two grounds and one hot wire was to reduce the potential for a short if wires break and touch the chassis. Ground wires can touch body metal with no issue, but if that +12V rail touches ground you're losing a fuse, so use caution.

I ran only two wires back to the dome light, one from the +12V dark blue wire, and another from the middle gray/purple wire for the dimming circuit. This makes the dome light fade on/off with the map lights when you unlock/lock the car, or open/close doors.

With this wiring, the new dome light won't come on when you turn on the individual map lights up front. If your dome light of choice has its own on/off switch, you may consider running the other solid ground (yellow/green) back as well so you can use that. Mine was sans-switch/buttons, so I kept it simple.

Step 4: Determine where to solder on your new dome light

Look at your new unit, and find the power hookup. On this particular part, there is a 4-pin connector as shown:


From this point of view, the pin on the far left is +12V, and the pin on the far right is for the dimming ground. You can see where the pins enter the PCB, that these outer pins are the only ones used. If you look closely you'll notice the inner two pins are unused, and just go into blank PCB. I assume on different models of this light that have buttons, these pins may be used for the solid ground or perhaps to communicate with the car's BCM. Doesn't matter for this application.

Step 5: Determine where you want to install the light


I decided to install the light kind of in the middle of the ceiling, at the top of the 'dome', as it is a 'dome light'. Just made sense to me. If you look inside most cars with dome lights, this is where they usually are located anyway. This particular light's inner 'reflector', which is more like a white plastic cone around the bulb, directs more light towards the back seat by design. After installing it, I can personally attest that it provides more than enough coverage from this position on the ceiling.

Now for the fun part...

44 Posts
Discussion Starter #3
Step 6: Maul your headliner

This is pretty much the point of no return. Once you know longitudinally where you want the light, make a small mark there with your pencil. Then, measure the headliner's width at that point, and mark the lateral 'halfway-point' on the ceiling. This should be dead-center on the headliner, if you sit in the middle rear seat it should lie directly in your line of view.

Now measure your light and pencil in a rough outline of it on the headliner as a cutting guide. You'll want to err towards keeping the hole smaller than the actual light, the material is flexible and will hug the light better when you shove it into place.

Once you've got an accurately-measured outline and you're happy with the positioning, it's time to fully commit. Grab the ol' X-Acto and go to town. Make sure to make full up-and-down sawing motions with the blade so you cut through the whole thing. Underneath the cloth is about 1cm of foam, and then backing that is stiff fiberglass-cardboard stuff. Fair warning, I did wind up with a few annoying fiberglass splinters between my fingers, but they went away!


Step 7: Modify headliner clearance

Once you cut into the headliner you may have a small heart attack like I did, when you realize that there is only about 1cm of room between the headliner and the roof. Fear not however! This is where the paper towels come in. Tear off 4 of those half-sheets they have now, and fold them into a square. Now keep folding that square in half until it's a tight 1"x1" wad. Make 3 more of these.

Now, shove each of the four paper towel wads up between the headliner and the roof panel, on each side of the hole you cut. Scooch them back into the void about 3", as you shove them further back you'll notice that they act as spacers and create just enough clearance for this light to fit in there. See pics below to see what I'm talking about:


Step 8: Run the wire through

We're starting to see the light at the end of the tunnel! Starting from the map light hole, since there's plenty of space to stick your hand up there, stick the wire(s) you're using up in there and start shoving them towards the hole you just cut. There's some weird padding surrounding the map light hole, I opted to shove my wires underneath it (between it and the headliner). Once you start getting the end of the wire near the new hole, fish around with your fingers until you can reach it and pull it through. If this isn't working, another method I've seen involves using an unraveled coat hanger as a fishwire to pull it through. Whatever works.


Step 9: Solder the wires to your new light

Self-explanatory, I just used my scissors to strip the wire. Make sure to tin your wires first!

I also zip-tied the end of the wire down to the PCB to eliminate the risk of screwing up the solder job.


Step 10: Install the dome light

Probably the most rewarding part. Carefully seat the light in the hole, tuck in the wire, and pop it into place! Mine turned out even better than I expected, it looks like it came with the car from the factory.


Step 11: Finish Install

Reinstall the outer map light frame, running the new wire through the big hole in the middle with the wire clip. Pop all four clips back into place, using the screwdriver to hold down the metal bracket.

Now all there's left to do is wire it in and put the map light back together. You can splice and solder, use plastic wire taps, etc, if you'd like. All I did was put the exposed end of each wire into the respective holes on the map light connector, and then shove the connector into its socket on the map light with the wires snugly installed. Unfortunately I didn't take any pictures of this, so you'll have to use your imaginations instead!

Now reinstall the map light, it just clips back in in reverse order. The bezel just pushes into place.

And there you go! Sit back and marvel at your work! Since I used the OEM part from a newer Focus, it looks factory. I honestly forgot it was even there until I parked later that night and could actually see my backseat!


Thanks for reading, hope you all enjoyed my first write-up, and good luck if you decide to try this yourself. I would 10/10 do it again!



271 Posts
I would add that if a person has access to a junkyard, there are lots of options, and the "medium light stone" interior color is found throughout a lot of FoMoCo models. Lincoln LS, 500/Taurus/Montego/Sable and Fusion/Milan are all fairly common in junkyards these days, and there might be a nice combo dome/map assembly that might work.

44 Posts
Discussion Starter #7
I would add that if a person has access to a junkyard, there are lots of options, and the "medium light stone" interior color is found throughout a lot of FoMoCo models. Lincoln LS, 500/Taurus/Montego/Sable and Fusion/Milan are all fairly comming in junkyards these days, and there might be a nice combo dome/map assembly that might work.
Yeah, that's a good point! I was actually looking at the Fusion ones too. You really can use anything you want, and some of those models will have a switch so you can turn it on manually, or disable the door operation. I even momentarily considered doing two separate mini-van style ones on the side of the headliner (over the windows) but realized that would interfere with the airbags :oops:

2010 Focus SES 5spd
30 Posts
Great write up! I cant believe they didn't add one that year. Having one in the 10 SES is so helpful. Im with you on how long it took me to find the part number as well when I had to get a replacement
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