CREE for me?

[claylakem6]

Has anyone have any luck using the new LED/CREE bulbs in our cars without activating the Diagnostic panel? As these old and dim incandescent lights fail it would be nice to replace with brighter and longer lasting LED type with headlights excluded. Opportunities would be brake lights, back-up lights, turn signal, and especially the interior light! I have seen the ones for the tag light but I am no interested in having my tag number easier to read. :cop A special shout out to those attending SESF so we could see the difference.

[EuroGeorge]

Clay,

I have pondered the same thing. Maybe 12-13 times. Let's see if anyone has something to offer.

Geo

[bkats]

Perfect timing for this thread. I am currently in the process of upgrading all the rear-end lights to LED's (while simultaenously adding two more brake lights in the vacant rear fog positions). For whatever reason, I'm not eager to wire in a bunch of resistors and change out the flasher modules, so I'm leaving the turn signals as incandescents and installing some "CANBUS-rated" LED's (superbrightleds.com) in the brake and reverse lights. AFAIK, the CANBUS LED's either have a built-in resistor or have a higher resistance. Our cars don't use CANBUS, but I'm hoping the increase in resistance might work anyways. However, I hear the CANBUS LED's have a shorter life (not sure how much), so that takes away one of the LED advantages to some degree. For me, that's not such a big deal as my car is a daily, so I just want to make it as bright as possible so some idiot in their HID-equipped SUV doesn't crush my shark.

My car is in the shop right now, so I can't work on it. But if this turns out to be a plug-and-play solution, I'll certainly report back.

On an additional note, a respray of the reflectors and/or switching to higher output (not higher wattage) bulbs worked out for some others. I know a lot of our reflectors have significant overspray. Some of the motorsport editions were even painted black, I hear :confused.

Oh, and I have replaced the glove box light, the dome lights, the trunk light, and the hood light with LED replacements. I think they all look great. However, it is a bit hard to choose the right color for the interior dome light. I personally like to have a warmer light for the interior than the trunk/glovebox/underhood, but I haven't found an LED that's quite the right color. (Now that I'm thinking about it, I might switch it to amber to match the instrument lights...hmmm...) They all work though, no problems. Just remember, the dome light uses two bulbs. If you're looking to upgrade the light output from the dome light, you'll have a hard time. There's just the one driver's side (at least on my '89) and the lens/diffuser prevents the light from reaching real far. It's even worse on my car because I'm so damn short, my headrest blocks most of the light :).

Edit:

The brake lights still trigger the check panel. It appears the only solution is to wire in resistors to match the incandescent resistance. I will not be doing this because the check panel doesn't really bother me. However, I would still recommend switching the brake, tail, and reverse lights to LED if you drive at night or in traffic. Modern car headlights are much brighter than those of our 6er's vintage, and I've seen my girlfriend's '07 corolla headlights wash out my stock brake lights. The reverse lights are functionally much better as LED because they project the white light outward when you're backing up, rather than just a whiteish glow.

[Tnarkowicz]

Glad somebody asked, I can share my experience with LED lighting. I have tried with mixed (mostly good) success in installing LED lights, but it was a customised install.

Optical characteristics between traditional Incandescent lamps and LEDs plays a big part, as well as the optical design of our tail lights.

You will notice that the brake lights in our sixers have a large reflector behind them, whilst the tail lights have virtually no reflector, but have a fresnel lens built into the tail light lens in this area (those concentric rings on the lens). These behave very differently with LEDs.

The large reflector behind the brake lights suits incandescent lights very well as it focusses the rearward light from the bulb into a parallel beam, which provides a very uniform illumination once it goes through the red lens. Most LED lamps have beams facing only forward, which does not work well with this optical design. The reflector does very little and the light looks like a bright spot from behind the vehicle, rather than a uniform spread of light over the red lens area. Some LEDs replacement lamps are becoming available that have mulitple elements facing in various directions - I have not tried any of these.

The tail light on the other hand, with its fresnel lens, works very well with a single forward facing LED lamp. The fresnel lens converges the forward facing beam from the LED into a parallel beam, and illuminates the entire tail light area very well. No nasty small spots. I have used a Cree XML 1 Watt Red LED lamp in the tail light, and its exceptionally bright, at least 4 times brighter than the standard 5w bulb. Problem - my check panel warning for the tail lights now stays on all the time, the LEDs do not draw enough current to trip these.

My bulb was a home made job, using a standard bulb casing, 350ma driver and a LED on a customised heat sink. I'm sure you can buy similar LED lamps now.

I'd also recommend staying away from white LEDs. Comparing a 1W white LED with a 1W red LED, you are losing about a third of the brightness from the white LED once the light goes through the red lens - not so with a red LED, its producing all of its light in the red spectrum so is much brighter per Watt through a red lens.

The challenge with having a much brighter tail light is that you have to greatly increase the brightness of the Brake Lights to make them noticable again.
I chose to keep my brake lights stock incandescent, but installed an extra LED brake light just next to the brake light area, in that blank square portion of the tail light. I used 1 x 3 Watt Cree XML Red LED in each side mounted on aluminium strip for a heatsink, driven by a single 500mA off the shelf driver.

The same optical problem exists for this setup as for the brake lights - the forward facing LEDs just appear as bright spots. I solved this by using some fresnel lenses - those plastic book-mark sized flexible magnifiers that you see in chemist shops, office supply shops etc. I had to cut and glue two of these together for each lens in order to achieve the correct focal length, and I mounted them against the lens with blue tack . Works great, gives a uniform light over the lens area now. I also wired these so they stay on, but much dimmer, as an extra tail light. The driver circuit allows for this.

Overall the setup is surprisingly good, much brighter than stock, and gives instant brake light response compared with the slow turn-on of incandescent lamps. Keeping stock brake lights means I still have and extra level of backup should the LED circuit fail. Tail light is also interchangable with a normal lamp if required as it has not been modifed, also good as a backup.

Happy to provide more details, circuits, photos etc upon request.

[claylakem6]

The BavAuto LED bulb upgrade kit.......a little help Kai? Never mind it appears to be Japanese. Looks interesting. You get 5 different type bulb bases with each kit. 499664