Moderator Curtis Jacobson Portland Oregon (4593 posts) Registered: 10/12/2007 02:16AM Main British Car: 71 MGBGT, Buick 215 |
Easy LED Tail Lamps for MGB
Today's project was quick, easy, and inexpensive.
Quote from my photo gallery page, here: "It's 2014. Almost every single tractor trailer now uses light emitting diodes for rearward lighting. Mass production has advanced the state-of-the-art and brought costs down. Here, I've installed off-the-shelf six-LED sealed stop/turn/taillamp assemblies inside old Lucas housings. They're wired to illuminate in all three modes. MGB's original incandescent brake and tail lamp features remain, and a diode added to the wiring keeps that brake light isolated so it doesn't blink with the turn signals. Bottom line: more effective and much more reliable lighting. Total cost: less than $30." |
BlownMGB-V8 Jim Blackwood 9406 Gunpowder Rd., Florence, KY 41042 (6498 posts) Registered: 10/23/2007 12:59PM Main British Car: 1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS |
Re: Easy LED Tail Lamps for MGB
Very nice.
While we are on this, let's remember that Brian sells what looks to be a very well done LED tail-light conversion (with significantly more LEDs in it). I do not recall his selling price though. But well done Curtis. Very slick use of an existing product. Jim |
BlownMGB-V8 Jim Blackwood 9406 Gunpowder Rd., Florence, KY 41042 (6498 posts) Registered: 10/23/2007 12:59PM Main British Car: 1971 MGB Blown,Injected,Intercooled Buick 340/AA80E/JagIRS |
Re: Easy LED Tail Lamps for MGB
Curtis, can you give some more info about the lamp assemblies used (and maybe a dusk-time photo)? Plus maybe where you got them (Truck stop?)
Thanks? Jim |
mgb260 Jim Nichols Sequim,WA (2479 posts) Registered: 02/29/2008 08:29PM Main British Car: 1973 MGB roadster 260 Ford V8 |
Re: Easy LED Tail Lamps for MGB
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Moderator Curtis Jacobson Portland Oregon (4593 posts) Registered: 10/12/2007 02:16AM Main British Car: 71 MGBGT, Buick 215 |
Re: Easy LED Tail Lamps for MGB
LED tail lights demo video:
(If the blink rate seems irregular, it's a download speed issue with the video. Just wait a second and restart the video.) I used Optronics brand lamps, but you could use Truck-Lite, Grote, Peterson, or some other brand. The oval size/shape is an industry standard, but lens height and wiring/connectors vary. These lamps have a molded-in connector that lined up with the existing holes in my MG's body. I didn't make any mods whatsoever to the Optronics lamp or to the MG bodywork. The Optronics lamp housings are completely sealed, which I think is important because the Lucas housings tend to leak. Optronics is an American company, but these particular lamps were made in Taiwan. Advance Auto sells them, but they're cheaper online. I bought mine kitted with wiring and mounting grommets (which I didn't use) - here - for $27.19/pair. I ended up adding a second diode per side. Here's a sketch of what the wiring looks like, per side: I used diodes that I already had laying around. They're Pektron part number A75-294. It turns out, they're an original MGB part that Moss sells for $32.25 each (part number 181-855.) As much as I love and admire Moss, that's obviously an outrageous price. I phoned my local Volvo Trucks dealership. They sell the exact same part for $8.27 each (as Volvo part number 1578857). And that's a dealership price. I bet if you shop around, you can probably find Pektron diodes for about $2 each. The Pektron parts are convenient to use because they have spade terminals already, but they're just diodes! Edited 3 time(s). Last edit at 05/13/2014 12:33PM by Moderator. |
MGBV8 Carl Floyd Kingsport, TN (4556 posts) Registered: 10/23/2007 11:32PM Main British Car: 1979 MGB Buick 215 |
Re: Easy LED Tail Lamps for MGB
Thanks for the video! I was going to ask about some pics of them in action. Snuck in a bonus exhaust tone audio for good measure. ;)
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Moderator Curtis Jacobson Portland Oregon (4593 posts) Registered: 10/12/2007 02:16AM Main British Car: 71 MGBGT, Buick 215 |
Re: Easy LED Tail Lamps for MGB
Diode "B" ensures that your front signal light will still blink so that people ahead of you will see you're turning.
As for legality: as long as I signal before my turn, I'm legal. I could use my arm or a semaphore flag or whatever. I should of course be signaling turns well before before applying brakes. If I thought this wiring were a problem, the easiest way to rectify it would be to simply disconnect the wire between my incandescent brake lamp (above) and my LED brake/turn lamp (below). I could do so in two seconds without tools by simply unplugging diode "A". My LED turn signal would still be brighter than the 1156 bulb it replaced AND I'd still be using it as a second marker lamp too. Alternatively, I could add relays to my wiring to make the rear turn signals override the brake lights. |
DiDueColpi Fred Key West coast - Canada (1384 posts) Registered: 05/14/2010 03:06AM Main British Car: I really thought that I'd be an action figure by now! |
Re: Easy LED Tail Lamps for MGB
No need for relays Curtis, have a look at this.
Simply by adding two more diodes... 1N4- types should be enough and the're only $3.50 for 20 And connecting them this way... Will make all the lights work as Mr Lucas intended. The only caveat is that an incandescent bulb is needed somewhere in the turn signal circuit in order to supply a ground. I'm assuming the front signal is still this way so that will work just fine. Otherwise a loading resistor will be needed. Whats happening is. On a turn, the led module is grounding through the stop light bulb. And the turn signal flashes the led. On a stop, the led module grounds through the turn signal bulb. And the stop light powers the led. On stopping with a turn, the stop light powers the led and the signal light alternates power and ground causing the led to flash. Flashing on a stop will be reversed in relation to the front lights. but who really cares. Hope that makes some sense as I may have consumed a Scotchy Scotch or two. Cheers Fred |
NCtim Tim Shumbera Western North Carolina (239 posts) Registered: 01/19/2012 04:35PM Main British Car: |
Re: Easy LED Tail Lamps for MGB
Okay Fred,
I've looked at this schematic of yours a bunch of times and each time I end up being confused by another aspect. Are the grounds for the leds running back to the positive/power source? I'm no electrical whiz but maybe this is some voodoo with leds? Tim |
lars49 Larry Barnes Colorado Springs (177 posts) Registered: 06/11/2009 02:12PM Main British Car: 1980 MGB GM LA1 3400 V6 |
Re: Easy LED Tail Lamps for MGB
Tim
Current flows through diodes in the direction of the arrow. Remember that the lamp ground is the car chassis. |
Moderator Curtis Jacobson Portland Oregon (4593 posts) Registered: 10/12/2007 02:16AM Main British Car: 71 MGBGT, Buick 215 |
Re: Easy LED Tail Lamps for MGB
Fred, you're brilliant!
I finally got around to wiring in the additional diodes. I'm happy to report that the improved schematic works very nicely. |
NCtim Tim Shumbera Western North Carolina (239 posts) Registered: 01/19/2012 04:35PM Main British Car: |
Re: Easy LED Tail Lamps for MGB
Thanks,
I've printed this out and have diodes, lamps and connectors in hand. I'll follow the schematic and report back. Tim |
pspeaks Paul Speaks Dallas, Texas (698 posts) Registered: 07/20/2009 06:40PM Main British Car: 1972 MGB-GT 1979 Ford 302 |
Re: Easy LED Tail Lamps for MGB
Thanks guys, I'm considering changing to early tail light assemblies and making the upgrade myself.
Paul |
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