LED Tail light problems

Hey guys,

I made a custom tail light for my touring trunk- I ordered three 6x6 LED lights (on a flat circuit board) from superbrightLEDs, with an 1157 plug end. Today, I wired them together, but when I plug the light in and turn the ignition on, the tail light just turns on at full intensity- it does not get brighter when I hit the front or rear brake (on the battery or while the bike is running).





I am 100% positive that the lights are all wired together correctly, and I spent most of the day working on doing it the right way- solder and heat shrink tape.

Do I need to throw a resistor in somewhere? I have the brake indicator light pulled from the front because LEDs set off the bulb out warning.

Any suggestions?

Color Codes On Most Kawasaki’s (written for 1980’s bikes)

HEADLIGHT
RED with BLACK stripe, High Beam.
RED with YELLOW stripe, Low Beam.
BLACK with YELLOW stripe, the ground circuit.

BRAKE/TAIL LIGHT Can be an # 1157 dual filament bulb
RED, Running or Tail Light.
BLUE,(sometimes with a Red stripe) Brake Light Circuit.
BLACK with YELLOW stripe, the ground circuit.

LEFT FRONT TURN SIGNAL Can be an #1157 dual filament bulb
GREEN, Left front turn signal circuit.
BLUE, Left front running light circuit.
BLACK with YELLOW stripe, the ground circuit.

RIGHT FRONT TURN SIGNAL Can be an # 1157 dual filament bulb
GREY, Right front turn signal circuit.
BLUE, Right front running light circuit.
BLACK with YELLOW stripe, the ground circuit.

LEFT REAR TURN SIGNAL Can be an #1156 single filament bulb
GREEN, Left rear turn signal circuit.
BLACK with YELLOW stripe, the ground circuit.

RIGHT REAR TURN SIGNAL Can be an #1156 single filament bulb
GREY, Right rear turn signal circuit.
BLACK with YELLOW stripe, the ground circuit.

After further inspection, 3 of the LEDs are not lit while plugged in. The first unlit bulb has a weird abscess looking thing inside. Would that cause the problem of a single intensity light?

Anyone have any ideas? Who's running a homemade LED tail light? *cough* Otto *cough*

Were all of the LED's you bought the same intensity? If so then they will power up at the same brightness. The 1157 bulb, with 2 elements, has 2 different watt filaments in one bulb. 2 different amounts of current draw. What you may have set up is 2 Identical circuits, this makes them the same brightness.
If you drop the current with a resistor, you will change the brightness. But then the current you were saving will disappear to some extent with the resistance.
2 Different LED's might be better, but I'm sure a resistor would work.

Motor Head wrote: Were all of the LED's you bought the same intensity? If so then they will power up at the same brightness. The 1157 bulb, with 2 elements, has 2 different watt filaments in one bulb. 2 different amounts of current draw. What you may have set up is 2 Identical circuits, this makes them the same brightness.
If you drop the current with a resistor, you will change the brightness. But then the current you were saving will disappear to some extent with the resistance.
2 Different LED's might be better, but I'm sure a resistor would work.

Oh, I didn't even think of that. The "bulbs (i.e. LED breadboards) should be the same, except two are 100 degree wide angle LEDs and one is a 15 degree narrow angle LEDs.

So they will have the same brightness then. Either re-order or use a resistor to drop the tail light circuit.

I didn't build my own LED taillight, but adapted a R-6 light to my bike. It started behaving strangely (ie solid flasher on one side, no flasher on the other brake lights working intermittently, etc.) What I discovered was that my bike had a bad regulator and was overcharging. I was getting above 17.5 VDC at 4000 rpm. That proved to be too much juice for the taillight. Moral of the story, check your charging system output if you haven't already. Seems prudent considering your impending trip.

testarossa wrote: I didn't build my own LED taillight, but adapted a R-6 light to my bike. It started behaving strangely (ie solid flasher on one side, no flasher on the other brake lights working intermittently, etc.) What I discovered was that my bike had a bad regulator and was overcharging. I was getting above 17.5 VDC at 4000 rpm. That proved to be too much juice for the taillight. Moral of the story, check your charging system output if you haven't already. Seems prudent considering your impending trip.

Yep, I have a new reg/rect. Sitting on the shelf NEXT to my bike :whistle:

I have a "normal" LED bulb (45 LEDs shaped like a bulb) which works fine, so I don't think it's voltage issues.

My LED light worked fine for a short while. How long have you been running the "normal" LED replacement bulb?

Oh yeah, don't forget to at least test fit that R/R before you leave. Some of the newer combo units require longer bolts. That wouldn't be an easy roadside fix if you didn't already have the hardware.

Not 100% positive but I've had the LED tail light on for at least 4 months.

The RR is on my plate this weekend. I have heated grips coming, should have them by this time next week- the RR goes on before any other electricity sucking equipment goes on.