RPMS Posted January 23, 2001 Share Posted January 23, 2001 Howdy, Gents. I see by some of the replies to my "turn signal indicator" post below that others have interest in doing an LED conversion for the taillights. At first I thought I'd be real sneaky and not tell anyone about my conversion plans until it was finished, but now I see that I'm probably not all that much ahead of the pack, so why not write about it? I have wanted to use LED's for my indicator lamps for quite a while now, even preceeding the appearance of them on the Cadillac DeVille (or whatever GM boat they're on). I've tried quite a few things, but the limiting factors are brightness and cost. You can buy pre-made 1" LED clusters that plug into the stock taillight sockets, but that doesn't really get you anything. You're still using the stock socket (which corrodes in time), you've got basically stock looking light pattern when you're done, and there aren't enough LED's in a 1" cluster to be bright enough. Frankly, if I'm going to spend $120 converting just the taillights, I sure don't want to end up with something that is ineffective and doesn't look any different! That gains me nothing. I don't want it to be gaudy, just different. So I disassembled the tail light, and made a PC board that fit inside the (approximately) 2" x 10" lens. With standard (read, "inexpensive") red LED's installed, it became immediately obvious that they wouldn't be bright enough. And with LED's, if you crank up the voltage you don't get a brighter light, you just get a bunch of dead LEDs. Okay, so the obvious answer is to use superbright, DOT-rated LED's. But at .33 each x 100 per lens x 4 lenses, that adds up to some serious money. BG Micro offers a cluster of 51 LED's (27 red, 24 green) in a two inch circle for about four bucks. Problem is, it's rated at 24 volts, and it's sealed in epoxy. Never one to be put off, I bought one and used an industrial-strength bandsaw to cut through the epoxy, exposing the circuit board. I re-wired the connections so the LED's were 5 or 6 to a string, hooked it up to 12 volts up that way, and was rewarded with brilliant red light for about a femtosecond, until the string burned out because I didn't use a current-limiting resistor like I was told to. Anyway, the problems with this method are twofold. Putting a 2" disk of LED's in place requires total disassembly of the taillight housing (difficult at best with 26 year old sealant), and sawing/re-wiring each cluster is a pain in the butt. The 1" cluster they offer is wired for 12-volts right out of the box, but it uses only six red LEDs. If i go that route, I'll need seven or eight per lens to do the job right. Also, I thought I could wire it so the green LED's would blink with the turn signals. That's possible, but very little (as in, "almost no") green light makes it through the red lens. You can see them flickering, but they're not bright enough to be effective as turn signals. A pity. SO... Has anyone else done any research on this stuff? I'd love to hear about it, if you have. It's such a sexy option. Done right, it's brighter than stock, it does away with the troublesome bulb sockets, the *blink* of turn signals and brake lights is very eye-catching, and they "never" burn out. As an added bonus, they give off the most incredibly striking blood red color behind stock lenses! If you're looking for a performance-enhancing aspect to this idea, the lower current draw of the LEDs allows more amperage to flow to your electronic ignition. How 'bout that? Scott Ferguson 1974 260-Z (awaiting V8 conversion) Quote Link to comment Share on other sites More sharing options...
Guest pauli Posted January 23, 2001 Share Posted January 23, 2001 why not snag some from a junkyard? leds already designed for automotive use will be able to stand up to current easy enough... Quote Link to comment Share on other sites More sharing options...
pparaska Posted January 23, 2001 Share Posted January 23, 2001 I've very interested in doing this. I looked around for LEDs that had high power in a long strip, but didn't find anything that wasn't expensive. I have some European 240 tail lights (from DrewZ - Thanks!) that I'd love to put bright LEDs in. I have them apart, so that's not an issue. I'd really like to find LEDs that put out white light, since the red lenses cut down on the brightness. And I have yellow turn signal lenses as well. ------------------ Pete Paraska - 73 540Z - Marathon Z Project pparaska@home.com Pete's V8 Datsun 240Z Pages Quote Link to comment Share on other sites More sharing options...
jeromio Posted January 23, 2001 Share Posted January 23, 2001 I've been looking at the back of my jacked up Z sitting in my garage and contemplating doing something interesting, but sort of subtle with the tail lights. I really like the look of the Lexus tail lights (on their new "3 series" car and their dorky Camry/SUV). The sort of round reflector inside a clear case look. It wouldn't be too hard to replicate the basic shape of the current Z Car tail light lenses in plexi or lexan. I'd do a more basic, boxy kind of shape though - but still with the same approximate shape to retain the rear black valance piece. Anyway, inside these housings would live simple, round, reflector tail lights, or LEDs. A red tail light, a larger red brake light, an amber turn signal and then maybe one of those little micro fog lights as a reverse light. They'd have to be mounted in something shiny, like a piece of polished aluminum or stainless. Anyway, I have a looooong ways to go on my car until I can focus on the appearance. (crap - had to edit, html is off?) [This message has been edited by jeromio (edited January 23, 2001).] Quote Link to comment Share on other sites More sharing options...
Owen Posted January 24, 2001 Share Posted January 24, 2001 I just copied and pasted this from my other post... "PS. speaking of LEDs, I was looking into putting LEDs in the tail lites, turn signal assemblies, etc. to get rid of those stupid automotive type connectors and bulbs used right now. I looked into Lambert Enterprises http://www.lambertenterprises.com/ but they are pretty expensive." I also checked out Sylvania's site but not much info. My best bet would be to find a junked car that has the LED's, but there's not too many newer cars in the yards near me. Owen ------------------ http://www.homestead.com/s30z/index.html Quote Link to comment Share on other sites More sharing options...
BLKMGK Posted January 25, 2001 Share Posted January 25, 2001 Don't look at cars - look at trucks! I'm seeing ALL sorts of LED signals on trucks aroundhere. They must be retrofitting them from somewhere - look to the trucking supply industry, surely there's a vendor or two out there. I'll look as I've got time out on the 'net but I'd bet that this would work fine... Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 25, 2001 Share Posted January 25, 2001 That's where I got the idea actually.... saw a truck on the interstate with them. Beside the truck, I could see they were round with the LEDs shaped in a 8 or 10 pointed start pattern. About 4-5 LEDs in each leg of the star. From more than 20m or so away they looked like normal lights. I like the instant turn-on, all soldered connection(no sockets to corrode), and never having to worry about changing the bulbs. ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 25, 2001 Share Posted January 25, 2001 Just looking through catalogs....... t2 1/2 size LEDs (8mm diameter) "xtra bright red" LEDs are $0.19 each for 100 or more. 100mcd. t34 1/4 red (10mm diameter) are 200mcd and same price. Could easily do up a taillight cheap with those.... Damn! They have 2000mcd LEDs also for $0.25 each for 100 or more. That's a big step up! Cut breadboard to fit in lens, solder in as many LEDs as will fit, wire it up with a resistor, and you're good to go! ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
pparaska Posted January 25, 2001 Share Posted January 25, 2001 Yep, I was on Allied or some other electronics vendor site and saw those. I'd thought about making my own strips and I might do that. Anybody ever seen Clear LEDs that put out white light? They may not exist as this might not be possible with how LEDs make photons. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 25, 2001 Share Posted January 25, 2001 This same catalog has white ones - 3700 mcd. Dayum!! But they're $2.95 for 100 or more. A bit pricey for my tastes. ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
pparaska Posted January 25, 2001 Share Posted January 25, 2001 Cool, what catalog? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 25, 2001 Share Posted January 25, 2001 Jameco. www.jameco.com You can even order online! The part #s of interest are: 142885 142893 119634 138683 You think white ones in the taillights would be better? They have some crazy bright orange ones(9300 mcd!) that would make good turn signals maybe..... I may just have to order a handfull and see just how bright they are. ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
pparaska Posted January 25, 2001 Share Posted January 25, 2001 I've been looking around at Jameco and http://www.alliedelec.com . LEDs brightness is measured in mcd, or milli-candela = 0.001*candela Incandesent bulbs are rated in mean spherical candela (MSCD). Note that MSCD here = 1000 mcd. I checked the output of the 1157 tail light bulb (I think the 240Z specs a different one, but this is a common replacement) at: Sylvania 1157 specs and as you can see the running light filament is 3 candela (3000 mcd) and the brake/turn filament is 23 candela (23000) So it'd take 2 2000 mcd Ultra Bright Red LEDs (Jameco PN 152805) to do the running light filament intensity, and 11 or so of them to do the turn signal filament intensity. That says nothing about the viewing angle dependence of the LEDs, but that's probably not important. Anyway, the 152805 is $.29 a piece for 10 to 100, so it's a pretty cheap deal. Do like Morgan said and get some perforated electronics board and solder them up on a strip. Then you'd need to figure out how to drive the different modes (running versus brake/turn). I kind of like the way the Caddy's lights just get brighter going from running to brake light. It'd be cool to have a circuit to vary the driver voltage to the LEDs based on the mode of operation. I think I've seen something like that on one of the sites for harleys or street rod use of LEDs. White emitting LEDs are stinking expensive. Yellow is about the same as red, for my Euro tail light lenses. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 25, 2001 Share Posted January 25, 2001 Sweet! I'll say it again, cut some perfboard to fit inside the taillights(after you cut the back portion of the taillight out) and solder the leds onto them and wire them up. You can fill the entire taillight lens like that and it'll look pretty good I think. Put the board in the lens with some silicon caulk type stuff, and paint(or whatever) the rear part inside the car to keep the light out of the hatch area. You could also re-arrange the lights like I did, it makes them much more visible and makes your brake lights much more noticable - I wire mine just like the 84-86 z31 taillights are. And no goofy dual-use filaments like the stock wiring! I may very have to undertake this, instant-on, no corrosion, and no bulbs to change sounds great to me! ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
Owen Posted January 26, 2001 Share Posted January 26, 2001 OK, who can make some for those of who hate to solder? For turn signals, LEDs are directional therefore the perforated board would have to be curved (front turn signal) to fill the lens properly? Owen ------------------ http://www.homestead.com/s30z/index.html Quote Link to comment Share on other sites More sharing options...
RPMS Posted January 26, 2001 Author Share Posted January 26, 2001 Wow! I didn't think there was this much interest in LED lighting. Well, here's what else I can contribute. As several people have mentioned, white LED's are about 30 times the cost of red ones, so that avenue is out for most folks. Radio Shack has 6" x 10" perforated board for around three bucks, and each tail lens measures about 2" x 10" inside. That means that two sheets of perf board is plenty to do the rear taillights. For the cornering lights, you're on your own. I have no clue how to make perf board bend the correct amount. It's an epoxy formulation, so I don't believe you could heat and bend it. Anyone have any suggestions? Where voltage is concerned, my experiments showed that if you wire 5 lights in series, it comes out pretty well. More, and they get dimmer. Less, and they blow out. Problem is, if you use regular LED's, even the "xtra bright" ones that Morgan mentions, they're not bright enough. 100 mcd is truly weenie. The DOT ones that the truckers use are somewhere on the order of 1,500 mcd each. Even when I crammed as many LED's as possible onto the board, regular ones just didn't cut the mustard. The LED side was noticeably dimmer than the incandescent side at night. During the day, I'm sure they wouldn't be visible enough. For the turn signals, the bright yellow/orange LED's would be ideal. As long as the color of the LED is roughly the same as the color of the lens, you'll be okay. It's when you try to pass green light through a red lens that nothing comes through. Or vice versa. There are indeed LED retrofits already available - if you drive a Freightliner. A 4" pre-made cluster runs anywhere from $30 to $40 at Flying J or Petro. They ain't cheap. Now, if you could find a way to step up the power to 24 volts, I'm sure that the large clusters that BG Micro sells would provide ample light. Five 2" disks per side would be quite striking, I think. Anyone here have the electrical know-how to do this? Scott Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted January 26, 2001 Share Posted January 26, 2001 So, how many people would be interested in buying a LED cluster that fits behind the taillight lenses? You would have to cut the rear of the lights off and silicone the LED stuff in place. It'd be easy to make, and fairly easy to install. And best of all I have the resources readily available to make them a lot at a time ------------------ Morgan http://z31.com/~morgan/s30 http://carfiche.com Quote Link to comment Share on other sites More sharing options...
pparaska Posted January 27, 2001 Share Posted January 27, 2001 I'd be interested, but my situation with the Euro lenses would make mine a custom setup compared to the non-Euro lenses. This looks like a pretty cheap mod with a nice effect. One thing I've always disliked about the Z is that the tail and brake lights are dim on alot of the cars. Probably a combination of sooty lenses and bad ground wiring. Anyway, one thing this mod will do is allow us to fix that problem. Quote Link to comment Share on other sites More sharing options...
Owen Posted January 27, 2001 Share Posted January 27, 2001 If they're bright enough during the day, I would be interested too. Would these be parking lite, brake lite, turning signals? It sounds like just one board will be used for top or bottom, how will this work out? Wouldn't park+brake and park+turn have to be on two separate boards? What is the address/homepage for this Flying J or Petro place? Thanks, Owen PS regarding the curved lens up front, I think I read on Sylvania's site that they were using some kind of flexible string of lites that could be put anywhere. I would hit the junk yards but everything they have there is pre-1990... ------------------ http://www.homestead.com/s30z/index.html Quote Link to comment Share on other sites More sharing options...
pparaska Posted January 27, 2001 Share Posted January 27, 2001 You can run the LEDs at different voltages to get different brightnesses (within specs). This is how the tail lights on some of the new Caddy's work. Looks really sweet with very quick response of the LED to low/high/low when the brakes are tapped or the turn signals are on. Like I said, some place I've seen lately (I think it was one of the hotrod places on line that sell lots of LED lights have a circuit to hook you OE running/turn/brake light wires to in order to drive a single LED array to do this. Quote Link to comment Share on other sites More sharing options...
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