85-87 Town Car Rear Reflector

[Lutrova]

Here's a little photo-documentation on the rear reflector strip for 85-87 Town Cars, though I imagine the reflectors for all Box TCs are similar. None of this is rocket science, but I've got the pictures and figured it might help someone down the road. I undertook the project because of debris and some long-dead organic matter trapped behind the lenses.

The reflectors are held in place by 12 bolts, accessible from inside the trunk after removing the rear carpet and latch cover. There are also seven Phillips screws holding the bumper filler strip to the reflector, accessible from beneath the car. These should just require a simple screwdriver to remove, though if you have a trailer hitch there may be clearance issues on a few screws. I overcame this with a small ratcheting screwdriver from Harbor Freight.



Once everything's unbolted and unscrewed the whole unit should pull straight out. Don't forget to pop out the reverse lights.



In order to remove the actual reflective bits, the top and bottom aluminum trim pieces have to come off. These are each secured by eight retention clips and nuts, accessible from the reverse side of the assembly. Some of these nuts may be very close to the plastic housing, which can make it difficult to get a socket over them.



With the metal trim removed, the plastic lenses can come off. There are three panels, held on by 20-some metal clips and butyl tape around the entire perimeter. Remove the outer panels first, as they overlap the center. An angled pick tool or trim removal tool can help move things along, slipped behind the lens in the butyl channel. A little heat from a heat gun or hair dryer may make the butyl tape more pliable and ease removal, but since everything is plastic you don't want to go overboard with heat. Work your way around the perimeter of each panel and slowly free it from the tape and clips. This step is probably the riskiest of the whole process, as the red plastic lenses are fairly brittle.



Here's a closer shot of the metal clips and the butyl tape. Depending on how crusty things are, you might be able to reuse the butyl sealant. I opted to scrape it all out in order to better clean the reflector housing. Now would also be a good time to remove the rust from the clips - soaking in vinegar for a few days works well - and repainting them. You can see how as the clips rust, the reflective paint in the housing starts to run off. It's hardly noticeable when fully assembled, but you've come this far, so why not go all the way?



The final step in disassembly is to separate the reflector panels, which consist of a red lens and white diffuser. The diffuser is basically superglued to the lens at four points, two top and two bottom. A trim removal tool can slip between the two pieces at the top, and with a little torsion the glue should break free. The bottom connections are a little more fragile, but with some patience they should pop off too.



In total there are nine pieces to the unit, plus a couple dozen clips and fasteners. Reassembly should just be everything above in reverse. Note that there is some kind of sealant, possibly butyl, around the fasteners holding the reflector to the trunk. If this sealant is removed or falls off, a conduit is opened for water to enter the trunk.

[Lutrova]

After taking everything apart, I've been looking into lighting up the reflector with LEDs. The painted reflective trays are about 1/2" deep, with the diffuser panels sitting on top, which is enough clearance to edge light behind them. I bought a strip of 3528 waterproof red LEDs and mocked them up just along the top of each tray. They seem to be about as bright as the running lights. I was hoping they might be brighter, which would let me do something similar to the Mark VIII neon tail lights. It's possible a 5050 LED strip would put out enough light for that, but that would mean more current drawn too. The other issue would be which wires to tap into for the brake signal. I think the only option that wouldn't also flash with the turn signals is the high-mount brake lamps.



The hotspots from individual LEDs aren't quite as prominent in reality as in the picture. Still, I think I might be able to mitigate the effect by sanding the waterproof coating to diffuse the light. Failing that, it might be possible to secure some foam right in front of the lights. I'd like to avoid any sort of sheet or solid diffuser so as not to give another place for water to collect.

The red light seems to work well even across the clear reverse light lens. I haven't tested the reverse lights yet, but I expect they should be bright enough to overpower the LEDs and give off a clear, white light.

[VicCrownVic]

Neat.

If you can find it, this is a suggestion from someone else on the topic of LEDs in the cluster, stained glass paint is something that can be used to diffuse the light instead of (or along with) sanding the coating. White, gray, or light coat of black even might work. Might take some experimenting.

You could probably use a powered trailer wiring module if you wanted to go the brake and turn signal route. Just plug these lights into the trailer harness, and if you ever want to tow unplug these lights which, depending on the trailer, may be blocked anyway. I recently picked up a module with install kit for my '98 MGM (Tow Ready 119179/119180). It's more work to run power to the module, but since it is a powered module you wouldn't have the concern of drawing more current on the stock circuit(s).

[kishy]

Awesome mod. I've intended to do similar to my 84 but keep getting sidetracked by other stuff.
The 80-84 (80 being unique due to one special reflector) setup is different but the concept will likely translate based on what I've looked into so far.

[Lutrova]

Some sort of translucent spray paint could be a good option. I'll have to take a look at what's available.

I believe a trailer module would still run into the same problem as stock tail light wiring, which is getting a brake signal without a turn or hazard signal. Having the center flash with the hazards might not be so bad, but the turn signal flashing would require dividing the light strip between right and left, which leaves an awkward condition in the middle panel. That's why I'm thinking the high-mount brake light might be the best place to get a 'brake only' signal, though that wouldn't be an option on the 80-85's.

As for current draw, I saw somewhere that these 3528 strips should pull about 24 watts for the full 3 meters, or 2 amps at 12v. That should add no more than 1 amp to wherever I tap into, which is hopefully offset somewhat by switching over all the incandescent bulbs in the car to LEDs.

[gadget73]

just a matter of running a wire direct off the brake switch to the back. Thats all the 86+ cars did, it taps ahead of the turn switch.

Looks good. This was something I halfass considered doing but between laziness and fear of busting the lenses I never did. I was actually envisioning having to drill holes and mount the LED from the back side, but strips are a much better idea.

[kishy]

Thats all the 86+ cars did, it taps ahead of the turn switch.

There is a subtle change in there, though...86 flashes the middle brake light with the hazards. 91 doesn't. Somewhere in between, a change happened. Doesn't change the fact of what you said, but does change where they decided to borrow the voltage from.

It's also possible something is messed up in my 86 but given it's otherwise free of electrical gremlins I don't feel like that's likely.

[VicCrownVic]

Oh in that case, yes, the trailer module would not be what you want. A plain relay is more what you want if there is a concern of drawing too much current on the stock circuit.

[gadget73]

There is a subtle change in there, though...86 flashes the middle brake light with the hazards. 91 doesn't. Somewhere in between, a change happened. Doesn't change the fact of what you said, but does change where they decided to borrow the voltage from.

It's also possible something is messed up in my 86 but given it's otherwise free of electrical gremlins I don't feel like that's likely.

mine does that too, but its not like the hazards are used often enough for that to be a primary concern. Honestly if you really need the hazards, having the whole back end of the car flash is probably not the worst thing anyway.

[Lutrova]

It must've just been an 86 thing, because my 87 only turns on the front and rear turn signals with the hazards.

I made a second mock up tonight, this time running lighting around the entire perimeter of the reflector unit, or three sides per tray except for the center, which would be just top and bottom lit. The effect is a much more even light, and brighter. There seems to be enough light output now to rival the brake lights. LED hotspots are now an even greater problem, but I've hopefully got a solution coming in the mail this weekend - sanding the light strip waterproof covering was a bust.

My current plan for wiring is to divide the LEDs into four strips, one per side and two in the center, wiring them in parallel back to a single plug connector. The other side of the plug would split from two wires to three, with the ground going off to the ground points on the left side of the trunk. The positive wire would split in two, one wire running to the high-mount brake lamp and the other going to the rear side marker light. Both positive wires would be connected through diodes, while the marker light wire would have a resistor of some size in sequence as well. The resistor would probably have to be sized after installation so as to compare light output against the old running light brightness.

The end result should be lights that run at half brightness with the running lights, but fully light up when the brakes are depressed, and wiring that shouldn't mess anything up. But perhaps someone who knows more about electricity than I can set me straight if I've got the wrong idea.

[gadget73]

so basically the idea is to bypass the resistor when you hit the brakes to increase brightness? Should work, just have to size the resistor properly and heat sink it if needed. alternatively you could light half the strips off the running lights and the other half off the brake so it just doubles the light output that way. It wouldn't be as evenly lit though.

[Lutrova]

Made some progress in the last couple days. The reflective trays have been painted silver, as have the metal clips that hold the lenses in place. It wasn't the world's finest paint job, but as I may have said before, it's impossible to tell what the trays look like from the outside. More important, probably, is that the clips are cleaned up and protected from further rust.



I've wired up the LED light strips, routed through the back by four 5/32" holes drilled through the back of the trays. I'll seal them up with RTV once the light strips are permanently glued in place. All the wiring so far has been soldered. I'd never soldered anything before, but it wasn't too hard, and between the soldered connections and LEDs I'll hopefully never have to open things back up again.



It seems the outside surface of the diffuser panels is what gives the assembly its reflective properties, but it also creates a strange, streak-like effect when the LEDs backlight it. I got some translucent film off Amazon, the sort of stuff you put on windows for privacy. It remains to be seen just how well it will stick to the diffuser panel, but by laying it over top I can eliminate all of the streaking and probably 80% of the LED hotspots. And that's probably good enough for me. Below you can kind of see the streaking on the center and right panel, while the left has the privacy film in place.



I've been waffling on how to dim the lights for a running light. Using a resistor should work, but like Gadget said, there's the question of sizing it and then dumping excess heat. The light strip I got off Amazon has no data sheet, and I have no idea what I'm doing with electricity, so sizing the resistor would probably involve a lot of trial and error. Instead, I'm thinking of using a PWM. Diode Dynamics makes one with a bypass for automotive use, which appears to do exactly what I'm aiming for. So now instead of having to use diodes and resistors, I'll just wire the LED positive to the PWM dimmer, and from the dimmer tap into running lights, high brake, and a ground. Should be a lot cleaner in the end and allow for adjustments to the dimmed level at any point.

[gadget73]

PWM would be the better way. LED don't really dim so much on voltage as they do on current. Below a certain voltage they basically just turn off so sizing the resistor can be touchy. would be different for each section if the LED count was different too

[Lutrova]

It's finally done. And I'm pretty satisfied with how it's turned out, too.



First, here's a shot of one of the diffuser panels showing the difference between the baseline reflectiveness and the effect of the translucent film. Again, it's anyone's guess whether the film will stay stuck to the plastic long term, as it's only held on by static. But so far it seems fairly robust.



I used a trim and badge adhesive to secure the LED light strips to the back trays. Just a thin layer should be more than enough to keep them secured. Durability is again unknown, but I'm hopeful that since this glue is meant for exterior automotive use it should be able to withstand extremes of heat and moisture. The retaining clips had to go in before the strips could be glued, which meant the butyl tape had to precede both of those steps. I chilled the tape in the fridge for a few hours before installing to limit its tackiness and masked off everything I wanted to keep clean. A 1/2" roll was cut lengthwise to fit in the channels, so a 1/4" wide roll would probably be the better move if you're buying it for this project.

Once the butyl tape, retaining clips, and light strips are in, reassembly is basically just disassembly in reverse. The diffuser panels were superglued to the red lens covers, which have some particular geometry to help situate the diffusers correctly. It's still kind of a tricky operation, but one that needs to be done right to keep the two pieces from falling apart while trying to install them. The completed diffuser/lens pairs are then pressed into the butyl channels, starting with the center and then the ends. A little action from a heat gun makes the butyl tape very workable and the plastic parts should go in easily.



The car-side wiring was pretty straightforward. The PWM dimmer is suspended above the rear running light on the driver's side of the trunk. Power and ground to the reflector lighting runs out the left side of the photo, through a hole in the trunk, and by connector to the assembly and various LEDs. Dimmable power comes from the running light below, while bypassed, full strength power comes from the high mount brake light right above the spare tire. The common ground uses an existing ground point beside the power antenna. The dimmer allows for adjustment at any point to better match the tail light running intensity, which takes a little trial and error.



The final product with brakes applied.



And with only running lights on. Due to the way cell phone cameras work, it's difficult to convey the difference in intensity between running and brake lights, or the true appearance of the lights. But what I can show is that at both levels the LEDs manage to appear in the ballpark of the outer tail lights' brightness. My wife was at work when I finished this up, so a video showing everything in action will have to wait.

In broad daylight the reflector strip doesn't appear to be lit at all, which I think comes down to the edge lighting over point, and the lack of intensity of the 3528 LEDs. Perhaps 5050 LEDs would be bright enough to be seen during the day, or maybe an extra strip running right down the center of the trays. 5050s, though, would mean more power drawn, which would exceed the capacity of the PWM dimmer I chose, which might require splitting the wiring in two or some other creative solution. At any rate, running lights are more for inclement weather and night-time, where this setup should be more than adequate.

Also, although I don't have a picture here, the reverse lights read just fine, even with the brakes applied. The white reverse lens blends in nicely when not in use, or looks close enough to the rest so as not to call attention to itself.

All in all, the tail lights aren't as flashy as the latest Lincolns or Cadillacs, but they add a bit of flair while remaining sympathetic to the original design intent. And light bar-style tail lights are very in these days. Hopefully someone else here will undertake this mod. It could be especially sharp on an 80-84 Town Car, or maybe a Barge.

[Tiggie]

Looks great!