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Retrofitted Rear Reflectors with LEDs for Dynamic Turn Signals and Brake Lighting

29K views 86 replies 24 participants last post by  Northish  
#1 ·
Hey fellow RS drivers; just sharing a project I'm tackling. My car has been out of commission since 2/3/19 due to oil loss post head gasket recall. Ford stepped up and is replacing the engine, but the main hold-up has been an injector gasket kit that's been on backorder. Record setting snowfall this past month and my RS has had to sit it all out...

So, to pass the time and keep myself sane this past month I decided to A) learn how to use/code an Arduino and B) do something RS related while mine is being repaired. Those reflectors on the back of our cars always looked to me like they should have been illuminated from the factory so I decided to try do something about that.

I'm using an Arduino to control strips of addressable LEDs embedded in the reflectors (well one reflector so far as proof to myself I could do it.) The Arduino takes signals via a 4 channel optocoupler from the brake light, L & R signals, and the park light to determine how to light up the strips. A 12V to 5V buck powers the lights and Arduino.

Below is a short video of what I've put together so far:

Next steps are to open up the other reflector and embed a strip in it. Then I've got to make sure the optocoupler and voltage buck work, but I'll have to wait for my car to come back from the dealership for that.
 
#76 · (Edited)
It's very easy (like plug in a table lamp easy)...except the lens cutting part, I need to come up with a jig to make that happen in a quality-repeatable manner to make this re-producible with ease. If you want a kit that's plug and play, that can be done very easy, I could come up with a estimate later today if you want; or I may just sell the parts needed to make it work that aren't available for purchase on Amazon/elsewhere and just put up a affiliate links for you guys to use if you desire. I will also list the exact parts needed on my thread so it can be done on ones own time and budget as well; open-source for life.
 
#78 ·
It's very easy (like plug in a table lamp easy)...except the lens cutting part, I need to come up with a jig to make that happen in a quality-repeatable manner to make this a mass product. If you want a kit that's plug and play, that can be done very easy, I could come up with a estimate later today if you want; or I may just sell the parts needed to make it work that aren't available for purchase on Amazon/elsewhere and just put up a affiliate links for you guys to use if you desire. I will also list the exact parts needed on my thread so it can be done on ones own time and budget as well; open-source for life.
I have reflectors on order and can do that just fine, be happy to receive the rest!
 
#81 ·
Here is the wiring diagram I made to explain how to hook everything up:
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Here is the list of parts I used to get it all together:
Part NameSKU #VendorQuantity
Reflector, RIGHTCM5Z-13A565-DTasca
1​
Reflector, LEFTCM5Z-13A565-CTasca
1​
DotStar Digital LED Strip - Black 144 LED/m - 0.5 Meter
2328​
AdaFruit
2​
4 channel optocoupler that can handle up to 20V in and sends 5V outAmazon
1​
DC/DC buck converter that drops 14V input to 5V output and can handle 10 AmpsAmazon
1​
Arduino NanoAmazon
1​
Arduino Nano Extension board with I/O screw terminals (plug Arduino into it for easy to use screw terminals for hooking up)Amazon
1​
20 awg braided wire in several colorsAmazon
1​
16 awg stranded wire in assorted colors (for hooking up Converter and power to LED strips)Amazon
1​
Wire connectors JST SM style (assorted kits available to make your own plugs between devices, optional)Amazon
1​
Terminal crimping tool (for making connectors in line above)Amazon
1​
Curt Focus Trailer wiring harness kit (for easy connecting to tail lights without splicing)C56273eTrailer
1​
TE Connectivity Deutsch ICT Connectors / DTM06-4S (for waterproof connection in bumper)1734-1071-NDDigiKey
2​
TE Connectivity Deutsch ICT Connectors / DTM04-4P (for waterproof connection in bumper)1734-1081-NDDigiKey
2​
TE Connectivity Deutsch ICT Connectors / WM-4P (for waterproof connection in bumper)1734-1050-NDDigiKey
2​
TE Connectivity Deutsch ICT Connectors (VA) / 1060-20-0222 (for waterproof connection in bumper)1734-1147-1-NDDigiKey
8​
TE Connectivity Deutsch ICT Connectors (VA) / 1062-20-0222 (for waterproof connection in bumper)1734-1151-1-NDDigiKey
8​
TE Connectivity Deutsch ICT Connectors / WM-4S (for waterproof connection in bumper)1734-1051-NDDigiKey
2​
Heat shrink tubing assortmentAmazon
1​
J-B Weld 50133 Plastic Bonder Structural Adhesive Syringe - Tan - 25 ml (for sealing and reinforcing wires in reflector)Amazon
1​
470 Ohm resistors (for RC Filters)Amazon
4​
330 Ohm resistorsAmazon
2​
47 uF Capacitorv(for RC Filters)Amazon
4​
1000 uF Capacitor rated at 6.3V or higherAmazon
4​
PCB breadboard (for soldering RC Filters to)Amazon
1​
Project Box (to fit everything in)Amazon
1​
Wire wrap roll (fabric to protect wires and get a clean look)Amazon
1​
 
#82 ·
Here are some pictures of how I opened up the reflectors. Basically, there wasn't any easy way, so I used a soldering iron/plastic welder to make a groove and push aside some of the plastic (you'll want it to make re-sealing by re-melting it back together easier.) Then I used a Dremel with a thin plastic cutting wheel to carefully cut in the rest of the way. It's not easy or fast, so be very careful and take your time.
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#83 ·
Take the LED strips out of their supplied silicone sheath and remove ALL the silicone sealant sealing the wires into the sheath. You need it free of silicone to allow the epoxy to bond and seal the wires later.
Trim each LED strip down to 57 LEDs to fit lengthwise in the reflector.
The LED strips are just about 2mm too wide for the reflector, so you'll need to trim about 1mm off each side of the strips. You will be cutting into the copper on each side, no way around it, but be careful, take your time and it will still work fine if done right.
I bonded the LED strip to the reflector backing using 3M VHB tape. Then set the LED/reflector back into the clear reflector and clamp together.
Then start plastic welding the lenses back together and make sure you don't leave any holes. This takes forever, is tedious, and the vapors are not good for you. So again, there isn't an easy/fast way I could think of to do this.
Epoxy the wire exits from the housing to seal and support the wires. Again, no holes for water to get in!
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#84 ·
You'll have to drill a hole in each side of your bumper to pass the wires through and up to the tail light area. Here's a shot from behind the bumper showing the sweet waterproof connecters for that OEM look.
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#85 ·
Here are a couple final images of the RC Filter I ended up needing to add (can read about why earlier in the thread) and overall system consisting of 3 main pieces and a good place found to place them inside a project box in the trunk foam insert.
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#87 ·
Thanks! It's still all still going strong 5 yrs in. Still no plans to ever sell kits; there's not really any money in it TBH. Made the posts as a bit of a "how-to" in the event others wanted to give it a shot. As far as I know it's still an exclusive club of one.