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So I'm in the middle of designing and assembling a set of LED taillights for my 1:1 Barracuda. I had to make mounting bases for the LED's so I bought sheets of hi-temp ABS plastic sheet. I mounted my 1/8 straight router bit and went to town.

Here's the preliminary bases. Once I drill the mounting holes for the bulbs I'll shoot it with ALCLAD to chrome the backing, and seal it. The LED bulbs operate at like 91 degrees.. doubt heat will be an issue. The difference in brightness is amazing..

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Here's my prototype set wired up

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And LED reverse lights.. After doing some research I can't believe how simple it is to do. If anyone is interested shoot me a PM.

23441590063915-vi.jpg

But what I learned today was that you CAN cut sheets of plastic on a table router almost exactly to size. Being a model builder definitely gives me an edge do this. I have to make a set for my buddy's `64 Savoy next. THIS is the kind of stuff that kills my model building time. Plus I'm restoring a set of grilles in the garage, plus I'm gathering parts for next season..

It never ends.

Edited by FASTBACK340
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That's lookin' good John, and I really enjoyed working on 1:1 cars when I was younger. Now, not so much as I have a mechanic that does a great job and that I can trust.

Trust is the hard part. I tell my customers all the time that I'm a consumer too and have to rely on others for their services. Roofer, plumber, concrete, etc. I have to trust too. While my shop's services aren't cheap, we treat our customers cars like our own. Believe me, I see what goes on and it's night & day from the Stealerships…….

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I made a set of LED taillights (using the OEM glass "Plymouth" lettered lenses) for the 354 Hemi-powered '33 Plymouth we're building. You're right about the skills developed during model building transferring over to detail work on the 1:1s. LEDs and resistors are assembled on a custom board, a red lucite inter-lens intensifies the color (the old red-glass Plymouth lenses are a little weak, color-wise).

DSCN3573_zpsnwo8yfz1.jpg

Edited by Ace-Garageguy
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are you putting a resistor on each LED or one resistor for a group of LED's?

Or are you using 12v tolerant LED's with the resistor already built in?

What type of weatherproofing are you using?

You may want to investigate "conformal coating" if you are doing this for customers where you may be liable for unfortunate failures.

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are you putting a resistor on each LED or one resistor for a group of LED's?

Or are you using 12v tolerant LED's with the resistor already built in?

What type of weatherproofing are you using?

You may want to investigate "conformal coating" if you are doing this for customers where you may be liable for unfortunate failures.

What I'm building fits inside the weather-proof assembly and will have bayonet base leads to plug into the factory sockets.

The first prototype I built was way-over engineered. Calculating forward voltage times bulbs and milliamperes draw and wiring resistors. Instead I found pre-assembled LED bulbs with resistors already soldered and shrink-wrapped together. Just wire them in parallel and be done. No calculating forward voltage or packaging resistors.

And as far as "conformal coating" I'm just replacing a fragile glass bulb and thin filament with a cool running, efficient, BRIGHTER light source that doesn't compromise the original lenses optic or reflectorized qualities. Plus it last longer. Not too worried about it. Besides, I'm just doing this for me and so far 2 friends (another '68 'Cuda and a '64 Savoy)

Although there IS a market for '68 'Cuda's

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I made a set of LED taillights (using the OEM glass "Plymouth" lettered lenses) for the 354 Hemi-powered '33 Plymouth we're building. You're right about the skills developed during model building transferring over to detail work on the 1:1s. LEDs and resistors are assembled on a custom board, a red lucite inter-lens intensifies the color (the old red-glass Plymouth lenses are a little weak, color-wise).

Did you start out with white or red LED bulbs? I'm using the white bulbs for the reverse lights and red for the tail lights. Also what size bulbs? My first test shot I made used 68 5mm bulbs that was like staring into the sun. Now I'm using 48 3mm bulbs for the tail lights. And are these combination brake/tail lights? If so, what dropping resistor size did you use on the tail light side?

Just curious!

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Did you start out with white or red LED bulbs? I'm using the white bulbs for the reverse lights and red for the tail lights. Also what size bulbs? My first test shot I made used 68 5mm bulbs that was like staring into the sun. Now I'm using 48 3mm bulbs for the tail lights. And are these combination brake/tail lights? If so, what dropping resistor size did you use on the tail light side?

Just curious!

It's been maybe 3 years since I made the things, and all the info is in the shop notes, which are in the shop. Yes, they are combo tail / brake lights. Probably used white 20mA or 30mA 5mm leds...definitely white. I started by copying the circuit on a commercial set we had in stock for another car, modifying as I went. Probably kinda overkill, but I had custom PC boards (etched, really) made by a friend, rather than using perf-board. The whole mess went through several iterations until I was entirely happy with the look and brightness. I don't recall all the specs on the bits, but I do remember I used diodes to keep the tailights / brakelights from backfeeding through each other. Also used a clear diffuser that masks the individual LEDs and makes the old lenses glow evenly...and bright. The car owner was very insistent that he wanted lights as bright as LEDs that didn't look like LEDs.

P72503740.jpg

Edited by Ace-Garageguy
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Yeah, you need the diodes for sure, but I haven't tested the tail light resistor needed. I had used prototype board for the initial one, but what a PIA it was to trim. I'm going with the hi-temp ABS and mounting the LED's directly to it. Infiniti does it that way on the FX-35 without issue.

The tail lights on '68 Barracuda's are so small they need to be bright. These will fix that. The reverse lights suck too so I'm upgrading them too. Add in I'm upgrading to rear discs and a Corvette master cylinder, line loc, and H-4 headlights and it's all safety goodies this winter.

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Once you've established the correct forward voltage across whatever LEDs you are using, the practical solution to determining the amount of dimming-effect you'll get with a load resistor on the running light power supply side is experimentation. Too much drop across your resistor and your LEDs won't light up at all. Not enough drop and there won't be enough difference in intensity of the light output.

I usually cut the prefboard with a cutoff wheel (full size or Dremel) and finish trim with right-angle die-grinders, etc. Makes nice clean edges.

This circuit uses multiple 220 ohm, 1/4 watt resistors to maintain the correct forward voltage across the LEDs and one more to provide the dimming effect in the tail-light power supply. Unfortunately, the specifics of the LEDs aren't shown.

As no two custom installations are going to be identical as far as number and type of LEDs, trial and error is going to be your best bet. Used to be a little easier to do this stuff when Radio Shack actually sold electronic components, but all of my local ones are just toy and phone stores now.

circuit.jpg

Edited by Ace-Garageguy
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I used this site http://ledcalc.com to determine the resistors needed on the prototype set. The lights I have now have individual resistors soldered (and shrink wrapped!) to each bulb. All I have to do is wire them in parallel, install the tail light resistor, and diodes. No calculating…. no marathon soldering sessions.

Edited by FASTBACK340
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Here's the wiring on the first board. I know it's a rats nest…. but I was experimenting.

46443989906202-vi.jpg

Now all I have to do is connect all the reds and all the blacks and be done…. except for the diodes and dropping resistor for the taillights.

46443989906606-vi.jpg

Edited by FASTBACK340
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Alternatively, if you want real chrome, Something that I've used to "rechrome" headlight housings is a product called "trim-brite" And it's actual metal but very thin and with adhesive on the back of it. It's marketed as a type of rocker panel decor.

It comes in 6" widths, several feet long. I've cut templates out and restored the headlights on my Lincoln Mark VIII (to which replacements are not available)

So long as you prep and thoroughly clean the surface, that stuff sticks really, really well once applied.

http://www.oreillyauto.com/site/c/detail/TRM0/T1830/N0546.oap?pt=N0546&ppt=C0065

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The chroming might not even be necessary. Once I get a set operating I'm going to test them with & without Alclad. The reflector isn't really needed as there's more and brighter light sources illuminating the opening. Infiniti mounts their rear lamp bulbs directly to white plastic, as do Dakota Digital on the last set I installed in a `78 Firebird Formula.

What's stopping me from assembling everything is the stepped-drill I need to mount the bulbs, which is at work, 28 miles away …..with a blizzard about to ruin the next few days out here.

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