Joined: Wed Dec 21 2005, 07:34AM
Location: indiana
Posts: 791
The brakelites in my 300L have never been that impressive. Chrome paint in the housings would help, but I want something more. I've evaluated a few of the plug-in bulb-replacement LEDs, and they're generally less bright. You still get the LED's instant-on, and they're maybe good enough for nighttime, but not good enough for daylight brakelites IMHO. So not an option (although those designs continue to get better).
So here's a little experiment I've been doing for some LED brakelites. With all the new LED modules flooding the market, with lots of sizes/shapes (and cheap prices!) I bought some stuff to play with and see how it works. It should be pretty simple, especially on such a large light, to just put a string of modules in there, right?
But it's not, the devil's in the details. •The lens is not uniformly fluted side-side, there are some 'gaps', and all the LEDs really need to hide behind the fluting, otherwise they show up as dots, so that was a challenge to get uniformity in appearance. And the fluting is sometimes in groups of 3 lines, sometimes 2. Tough to get a fixed-shape module to have all the LEDs behind flutes, but I managed (eventually). •There are 2 reflectors in there also (hard to see in the pics) and the LEDs can't be behind them or it also hurts uniformity. •The curved end is a challenge to uniformity, and the whole lens/housing actually tapers slightly toward that end (by about 1/8"!). This taper was squeezing the modules right on the edges of the reflectors, which are 1/2-way up the lens. •And everything I've fiddled with requires mounting something inside the housing, and drilling holes that then need to be sealed with rubber washers. I wanted something that could be installed easily, or at least without permanent mods. •And it all needs to be deep into the housing to fit behind the scalloped lens. And the housing has curved & stepped areas that make recessing the assembly a challenge.
And in addition to all that: •I have not yet figured out how I want to handle the dual intensity function. •I may PWM all of them down for taillights (or use a resistor, but the ohmage is TBD), then full-signal to do turn/brakelites. •Or I may put 1/3-1/2 of them on for tails, then turn on remainder for turn/brake. That qty-balance will be totally a visual experiment in trial-error. •They have to be reliable, as there won't be an easy option to re-install a light bulb in along the road, so the modules must be wired such that they won't all die at once (not a big hurdle, though).
I got about 75% of the way there and wasn't seeing the finish line, or even if I was on the best path by using these particular modules. I'm pleased with the appearance, and the overall light output seems spot-on, but I'm frustrated with all of the mounting rigamarole. And I still need to seat it all a little deeper, which means a smaller mounting plate, which will start putting the modules into the housing walls (it tapers due to diecasting draft), and I'm starting to smush on the wiring nubs that come out of the modules, too. Wifey suggested I box/shelve it for awhile and wait for some inspiration/new ideas to kick in. Sometimes she's smarter than me, that's for sure. I have a few more ideas rolling around, and have some totally different LED chips due in a few weeks. Those will basically be a start-over from a mounting perspective, but will be much smaller, fewer, and will therefore avoid the fluting-location issue. But they may require heatsinks, and the lighting output is unknown.
Here are some pics of full-intensity. LEDs are hard to photograph vs how the eye perceives them. The 2nd pic looks 'bulbier' than it really is, and the 3rd is the closest but it's not that intense. #4 is with no flash, and is completely exagerrated. This thing will not blind anyone behind me, that is a prime consideration to this experiment.
Anyway - maybe sometime this summer I'll be sporting a set of finished lites and can send some pics of them in operation in the car.
Joined: Sat Aug 19 2006, 05:03PM
Location: Ontario, Canada
Posts: 2919
Looks like a good start to me. I want to do something similar with my '66 taillights eventually, so I'll be interested to know what works for you and where you got your LEDs from.
The '66 taillights use two bulbs. I would like to arrange the LEDs into 3 or 4 groups so I can make the turn signals sequential. I have enough spare tail light housings that I'm not worried about doing irreversible modifications to a set.
Joined: Thu Mar 01 2007, 09:30PM
Location: Houston
Posts: 1735
I appreciate the work but really...I like the dim lights of yesterday's cars. The LED's are too bright and too"blingy" IMO
I'll add that the only lights on a car that are righteous are the headlights, cuz they allow you to drive at night. Rear lights? They serve only one purpose - make it easier for the cops to spot you when you're runnin'. The dimmer the better.
Joined: Sat Mar 04 2006, 08:01PM
Location: Tucson AZ
Posts: 171
gregcon wrote ... Rear lights? They serve only one purpose - make it easier for the cops to spot you when you're runnin'. The dimmer the better.
I don't know. I think having tail/brake lights bright enough to help keep idiots from rear ending my classic C a huge plus. Besides, you can always wire in a cut out for all lights but the headlights if you really want to run from the 5-O.
Joined: Wed Dec 21 2005, 07:34AM
Location: indiana
Posts: 791
Furious65 wrote ...
gregcon wrote ... Rear lights? They serve only one purpose - make it easier for the cops to spot you when you're runnin'. The dimmer the better.
I don't know. I think having tail/brake lights bright enough to help keep idiots from rear ending my classic C a huge plus. Besides, you can always wire in a cut out for all lights but the headlights if you really want to run from the 5-O.
Agreed. I'm more worried about soccer moms and texters than the cops at this point.
Joined: Wed Dec 21 2005, 07:34AM
Location: indiana
Posts: 791
300Rag wrote ...
Here's what I played with. I modified the bucket to accept a 6" oval LED light. I had to use clear since my lense is clear.
I have often lusted over those clear lenses in your sigpic! Nice work on the oval, I have that on my prospect list also. It definitely solves most of the DOT-compliance questions.
Mike66Chryslers wrote ...
Looks like a good start to me. I want to do something similar with my '66 taillights eventually, so I'll be interested to know what works for you and where you got your LEDs from.
The '66 taillights use two bulbs. I would like to arrange the LEDs into 3 or 4 groups so I can make the turn signals sequential. I have enough spare tail light housings that I'm not worried about doing irreversible modifications to a set.
It's kinda my hope that I can develop a recipe that can be applied to a variety of cars (C-bodies first, of course!) and differ only via the mounting method. I have a benchtop CNC machine that can knock out the vehicle-specific stuff as needed and maybe I can make a few $$ along the way. I've seen some sequencer modules out there for Mustangs and Imperials, so you probably have some options?
Joined: Sat Aug 19 2006, 05:03PM
Location: Ontario, Canada
Posts: 2919
Yes, I looked briefly and there are aftermarket sequencers for 2-, 3- and 4 bulbs per side. I think sequencing with only 2 bulbs wouldn't be worth the effort though, you really need at least 3 bulbs for the right look.
I thought this was an interesting read. It won't dissuade me from trying my own LED retrofit eventually, but testing for heat build-up and dimming with extended operation would be a good idea. There's surely more of a science to testing and certifying vehicle taillights now than there was when our cars were made, so a well though-out LED retrofit should be an improvement.
It's interesting that most of the drop-in LED replacement bulbs currently on the market aren't legal, but Philips makes LED replacements for 1156 and 1157 bulbs that are, and would probably work fine in our cars. As Daniel Stern says, taillights in older vehicles use simple reflectors and fresnel lenses to distribute the light.
Joined: Tue Oct 11 2005, 01:33AM
Location: Calgary, Alberta
Posts: 5893
Interesting read. I was a little surprised to learn that LED output is a function of temperature and that heat sinks are a must. Given our crazy climate, ie -40 to +100, LED operating temperature and thus light output will be problematic at best.
Another factor |'ve started to notice as my eyes get older, LED light is more difficult to see than old fashioned bulbs. Not sure why. I suspect LED's are monochromatic and if the eye has problems with a that specific color you see little light. Old fashioned bulbs throw out a wider light spectrum so that even if the eye can't see certain ranges it will still see the side scatter.
