Replacing tail lights with LED bulbs?

I have bought several led bulbs, and the cheap ones begin to flicker or strobe after a few weeks. the good ones are brighter than incandescent and likely will last as long as I have the car.

the "off-road use only" disclaimer is just to cover the seller's @$$, not because of any actual legal requirement. the exception is super bright headlight and fog bulbs which might blind oncoming traffic. some of those are illegally bright.

 

In the US, the legal requirements in question are found in Federal Motor Vehicle Safety Standard 108.

In section S6.4 there's a short introduction to the kinds of requirements for visibility and "effective projected luminous lens area" that apply to all the signals on a car that are there to be seen (as opposed to just helping you see).

A really bright, small projector might be OK for a headlamp as long as it throws enough light for you to see by, but as a taillight or turn signal or brake light, might be completely obscured to another driver by some narrow obstruction on a curved road. So, all of those marker and signal lights have to meet strict specs about distributing the light from the bulb evenly over a required minimum lens area, verified by photometry over a required range of viewing directions.

For anyone interested in how the photometry is done (I've always thought it's kind of fascinating, but I was a drama lighting tech in school), scroll down to S14.

The manufacturers meet the requirements either by molding the lenses with lots of tiny facets all individually aimed at the filament in the center of the bulb, or (the newer, sleeker look), using plain lenses and molding all the facets into the internal reflector ... or some combination of both.

Now, the standard does require (S14.2.1.6) that the design has to tolerate some variation in the manufacture of replacement bulbs. The whole reflector/lens design has to be able to do its job and pass the photometric tests when a replacement bulb's filament is as much as 0.010" out of the correct position.

And that's where an issue with the LED replacements comes in. In order to make an LED "bulb" throw light all around, it is usually a big blob with a bunch of LED chips mounted on its surface and facing in different directions. It may cast light in a lot of directions, and there may be no problem with the total amount of light given off, but pretty much none of those LED chips are going to be within 0.010" of the designed filament position, or emitting light in the direction the lens and reflector facets were computed for.

Will it light up and look bright? Probably. Will it meet the photometric requirement for uniformly lit lens area over the required viewing angles? Who knows? The LED bulb manufacturer doesn't, because they'd have to test their bulb in your car's reflectors and lenses (and, like, a thousand others). Hence the "off-road use only".

Ok, so you might install it, glance at it from the back, and think "looks fine to me." Maybe you'd be geeky enough to follow the photometry test requirements in S14 and prove that it totally is fine ... in your car. Not saying it can't be.

But that's the reason those LED bulbs say that.

-Chap

 

On a related note, where is the flasher? I contorted myself under the steering column with my head next to the brake pedal and stared up into that space, and didn't see a relay like the one I've seen in pictures I can find. It seems like the good pictures showing there the flasher relay is would be considered a functional work of art.

I've read through most of the threads where the relay is, but I can't find it. I've also tried the feel method to determine where the clicking sound is coming from, but nothing seems to be vibrating. No luck there either.

 

its behind the lower dash trim panel on the drivers side of the car, behind a metal plate that is secured by 3 10mm nuts.

next time in in that area of the car, ill try to remember to get a picture.
you will have to take the lower trim off in order to get to it.

almost behind the key slot on the australian spec cars.
not sure if the slot is the same on US cars, as we have a different power button position also....

jason.

 

Ah gotcha. I saw a similarly sized device that was immediately to the left of the steering column in between the fuse panel and the metal plate. It looks like I could just take the lower trim panel and three nuts holding that metal plate on and the relay would come right out. This is a US spec car where the power button and key slot is on the right side of the column. Thanks! Once the tap turn relay comes in, I'll snap a picture as I'm switching it out.

 

I have the tapturn too. You will like it I'm sure.

Jason.

 

I've replaced my relay as well. After you loosen the dash and remove the plate behind the 3 nuts, just turn on your emergency flashers and feel with your hands for the relay. You'll be able to feel the one that clicks.

 

Tell me if I'm being stupid but would high usage lights effect the battery of the car i.e. If you have all led more miles on ev mode etc or do the lights all run off the 12 v thanks

 

Leds do use less power than normal ones, but the difference in practice would so small as to be hardly noticeable.

Jason.

 

Yes that's cool I know they use less just thought may made a difference

 

Besides, the little effect it produces appears as gasoline / petrol consumption, not as a battery issue.

 

No worries I'm new to this just purchased one and collecting Monday so trying to find out lots of tips

 

There's no reason not not to get led replacements for most of the globes.
As long as you get ones that are bright enough. There are still some advantages.

Longevity being one of them. Cooler running another.

I have led globes in every single place in my car, with the exception of the headlights.
All other globes are led. The only reason I've held off on the headlights is that the replacements,
Would likely scatter light and blind oncoming traffic.

Jason.

 

Is that based on experience or just theory?

Theoretically LED should last longer than the car but most of car led bulbs seem fail lot faster than incandescent bulbs. Maybe if you spend 20e (22 dollars) on a pair of bulbs you could get something that would really last. If you do know a reasonable priced brand that still last could you name it?

 

You can't expect a cheap $5 eBay led to last. Not doing to happen.

My indicators and reverse globes were something like $50 per pair.
In no way cheap, but I'm confident they will last longer than I own the car for.

I've used such leds in most of my cars over the last 5 years or more, and never had issues.
I've only ever had to replace those cheap $5 ones. I got a cheap set and tried them as tail lights.
My thinking was they aren't super bright, so not being driven that hard.
Even those failed in only a few months.

I got a decent pair and haven't had to change them again in over 2.5 years.

All the interior leds were cheaper ones, as these are not as important if they fail. Just a little inconvenience.


Jason.

 

I replaced my stock headlights with these Lumen LED bulbs. They work very well. Lumen® - Toyota Prius 2015 G8 LED Headlight Conversion Kit

 

I mostly just meant those that replace 5w incandescent. For those 50 dollars (even Australian) is just too much for a pair of led bulbs.

I would just think that they could make something reliable for less than 15e ($17 US or $22 AUD).

Most of stores here just sell these 5…15e peace/pair LED bulbs but they all seem to have short life. Luckily it’s my friends how have bought those and not me. I do have those expensive LED bulbs in front parking lights and license plate bulbs.

 

These are what I have for the turn signals.

FOR 86/BRZ! 2X 7443/7440 50W OSRAM AMBER LED FRONT REAR TURN SIGNAL LIGHT BULBS | eBay

Same for the reverse, only white obviously.

I guess you get wat you pay for sometimes.

Jason.

 

Maybe, sometimes.

But for me it just doesn’t really make sense that they can sell car LED light bulb for couple of euros/dollars but then to get one that has reasonable lifespan you have to pay so much more. Actual cost of manufacturing can’t really be that much more. But I ques the prize is based one marketing and not manufacturing.