LED Brake Lights

[7783911]

do yu have any metrics to compare old light output against new?

[spoke]

Originally Posted by 7783911

do yu have any metrics to compare old light output against new?

A similar 914 fog light that I made with 8 LEDs running 500mA was about 2.5x brighter than the OEM bulb. This one is running 350mA so is less bright. I hope to make some measurement comparisons this weekend.

Built 2 boards. Will put them in my 930 this weekend and compare with the OEM bulb.

This board burns less than 9W whereas the OEM bulb burns 55W. Less than 20% of the OEM power.

[spoke]

Fits in the lens very nicely.

[spoke]

Been running the board in the fixture to see how hot things get.

Seeing temps about 35C above ambient which is good.

[spoke]

Put spade connectors on. The 12V needs a plain male spade and the ground gets a shielded male spade.



Connection is simple. Plug both wires into the mating wires. Lots of room to work with the wires.



Just have to make sure the wires are out of the way and reattach the lens.

[PabloX]

Sorry if this is a slight hijack.

Does anyone know how to wire the fog lights so they're independent of the headlights?

I'd like to wire them so they come on and off with the fog light switch, but also shut off with the ignition. Thoughts?

If this is better in a separate thread, just yell.

[spoke]

Here's the car with the LED foglight on the passenger side and the existing foglight on the driver side. The foglight bulb has a warm color and doesn't match the LED headlights or turnsignal running lights. The LED foglights match the headlight and turnsignal temperatures pretty well. The foglight LEDs are 5000K temperature.



Here's the light from the existing bulb. The intensity of the light at 1 meter is 140 Lux. I don't think I can compare this number to the LEDs since the lens is so pitted. I'll have to install a new lens and remeasure.



Here's the light from the LED foglight. It's difficult to see the difference since the camera is auto-adjusting the exposure. The LED is much brighter. At 1 meter, the light intensity is 1900 Lux. This is 10x the light from the existing bulb with a highly pitted lens.

The LED headlight from Carmagic was measured at 25000 Lux at 1 meter. The headlights are quite bright with a sharp upper cutoff.

[spoke]

Originally Posted by PabloX

Sorry if this is a slight hijack.

Does anyone know how to wire the fog lights so they're independent of the headlights?

I'd like to wire them so they come on and off with the fog light switch, but also shut off with the ignition. Thoughts?

If this is better in a separate thread, just yell.

I haven't looked at the exact wiring of my '86 930 but here is how the 914 is wired for its foglights and headlights. I think the 911 is similar to the 914 in that the headlights have to be on and the low beams on.

The 914 foglight will turn off if the high beams are on. I'll look into the wiring on the 930 and get back to you.

[7783911]

is your design only intended for later 911's or will that board work with earlier 911's with the lamp not integrated to the bumper?

[spoke]

Originally Posted by 7783911

is your design only intended for later 911's or will that board work with earlier 911's with the lamp not integrated to the bumper?

Not sure what the earlier 911 foglights look like. I'm gonna guess that this board shape will not fit. It's the size and shape of the board and the plastic bits it takes to hold the board in place that may need to be adjusted. The circuit could absolutely be used in the early 911.

[DNickel]

Definitely considering these
I have converted the my 88 to all LED inside and out but I can never find fog bulbs that are shallow enough and bright enough to convert the fogs. I'm running 6-6500K in the headlights so if yours are 5K that will be fairly close.
Also, the wiring of the fogs to be always on with the fog switch would be nice as I like the as DRL.

[7783911]

so on the 77 and older model which had "standalone/free hanging driver lights: the dimensions are

7 in wide
3.5 inch high
2 inch depth

[spoke]

Nice pictures. Thanks. Looks like a board could fit in it. The board would be unique to that fixture. If you can send a fixture to me to design with, I could design a board and in return I'll give you the first prototypes for free. I would need the fixture for a couple of months to do the design and testing.

[Canada Kev]

Originally Posted by PabloX

Sorry if this is a slight hijack.

Does anyone know how to wire the fog lights so they're independent of the headlights?

I'd like to wire them so they come on and off with the fog light switch, but also shut off with the ignition. Thoughts?

If this is better in a separate thread, just yell.

I have mine wired up to operate exactly like how you are asking for. There may be other ways to implement, but this is what I did: pull out the headlight switch and move the GREY wire (this should be the fog light relay trigger power source wire) to pin 75. That wire is likely currently on pin 56. That's all there is to it.

If you reference the chart below, you will see that pin 75 is energized whenever the ignition is ON and the headlight switch is in any of its positions: off, first detent and second detent. This will allow current to run from the headlight switch to any wire connected to pin 75 whenever those conditions are met, thus the fog light switch gets power at those times. Then the switch can send that electricity to the fog light relay to turn on the lights.

I suspect the current situation is that your grey wire is on pin 56. This pin, according to my chart, is energized only when the ignition is on and the headlight switch is at the second detent. That means the car has to be on (or the key in the on position) and the headlights on for the fog lights to work.



I hope that helps.

One last note is that the headlight switch comes out pretty easily. On my 1987 car, just pop out the little plastic headlight symbol from the rubber knob of the headlight switch with a small screwdriver or other little prying device. Under that, if my memory is correct, there should be a small circular nut screwed over the switch shaft. That nut is maybe 3/4 inches diameter with two small holes on its face 180 degrees across from each other. As that nut is flat other than the two holes, you must use something in those holes to turn the nut. I used some small needle nose pliers and poked the two tips of the jaws in there and used them to screw it out. Once you have that off, the switch should pull out from under and behind the dash. Mine came out easily, but watch that you don't disconnect or snag any of the half dozen wires attached to it. Mover your wires you wish and then put the switch back in the reverse method of removal. Maybe test that all works according to plan before you replace it to ensure correct operation.

[7783911]

PM sent re sending you might lamps

[spoke]

To compare the output of the LED fogs to the OEM, I need to clean up the reflector and install a new glass lens. The stock lens was cracked in 2 places and one of the cracks broke through to let water and dirt in.



To show the difference in the lenses, I put them on a patterned notebook. Can't even see what's under the stock lens



The stock (30+ years old) lens is more like a shade blocking light.



Cleaned up the reflector.



Now with the new lens, the bulb and fixture are visible. I will measure the output tonight when it's dark.

[spoke]

Had a chance to measure the output of the OEM bulb with the new lens on the driver side. Quite a bit of difference. Tonight I think I was a bit closer to the bulb (around 1 meter) since I measured 3000 Lux for the LED foglight (measured 1900 Lux before) and 1500 Lux for the OEM bulb. The bulb is much brighter with the new lens.

Looks like in direct comparison the LED foglight is 2x brighter than the OEM bulb with identical lenses burning less than 1/5 the power 9W vs. 55W.

[Canada Kev]

How is the heat on those LEDs in comparison to the bulbs? I changed my standard (55 watt?) bulbs to 35 W to eliminate any chance of their heat melting or distorting the plastic housing. I didn't personally have any issues, but I've heard others have. I often use them on the highway as daytime running lights, so they're on a lot.

[PabloX]

Originally Posted by Canada Kev

How is the heat on those LEDs in comparison to the bulbs? I changed my standard (55 watt?) bulbs to 35 W to eliminate any chance of their heat melting or distorting the plastic housing. I didn't personally have any issues, but I've heard others have. I often use them on the highway as daytime running lights, so they're on a lot.

I'm no EE, but Spoke mentions his LED replacement draws 9W and puts out more light. Any electricity that goes in and isn't converted to light has to be converted to heat.

So, the LEDs should run a lot cooler. The lower wattage should be better for the wiring as well.

[Arne2]

The heat is also spread out over the entire light, not concentrated as a bulb does.