Instructions for LED Headlight upgrade (1 Viewer)

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Well it’s better, I’ll run it like this for a bit and see how it is. Never you mind my broke oil pressure gauge.
4AC9B7D2-E281-4334-80F1-13B7C52F4417.jpeg
 

Advent

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I just followed @amw2320 ’s wiring diagram but used the JW Speaker harnesses directly:
323720C1-E53B-4087-979C-DBFC9AA1CF1A.jpeg


I used 2ea 6ohm resisters from a Sylvania kit meant for LED turn signal replacement bulbs, wired in series.

Seems to work great so far! Thanks everyone for your hard work figuring the circuit out!
 
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50ohms ended up not being enough. Still got blinded with the LED high beam indicator whenever I turned the high beams on. I ordered some 100ohm resistors and apparently misplaced them. So I soldered two 50ohm resistors back to back. Reduces the amps down to 0.13A oppose to 0.23A with just one 50ohm resistor. The dash indicator still comes on, so I'll report back to let you guys know how it turns out.

Being that the LED bulb only draws 0.01A I'm not sure I'll see a difference. If this doesn't work I'll give up and go back to incandescent
 

Spook50

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50ohms ended up not being enough. Still got blinded with the LED high beam indicator whenever I turned the high beams on. I ordered some 100ohm resistors and apparently misplaced them. So I soldered two 50ohm resistors back to back. Reduces the amps down to 0.13A oppose to 0.23A with just one 50ohm resistor. The dash indicator still comes on, so I'll report back to let you guys know how it turns out.

Being that the LED bulb only draws 0.01A I'm not sure I'll see a difference. If this doesn't work I'll give up and go back to incandescent
Yeah a resistor alone won't dim the LED as long as the voltage matches its operating voltage and the current available is equal to or more than it pulls. You'd need a PWM to "dim" it. A better option if you want to keep an LED in the indicator would be to find one with a lower lumen output, which is what I might do. The primary reason the resistor is used in the first place is to prevent blowing the fuses when you toggle high beams by pulling the stalk back. If you have an incandescent bulb in the dash, you could dim THAT by changing resistor values. I can't remember if the socket uses a 194 or a 168 bulb. They're the same dimensionally, but the 168 bulb is brighter and draws more current (also as a consequence, hotter). If the original design was for a 168 bulb, I would try a 194 bulb instead to see how you like it.
 
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Yeah a resistor alone won't dim the LED as long as the voltage matches its operating voltage and the current available is equal to or more than it pulls. You'd need a PWM to "dim" it. A better option if you want to keep an LED in the indicator would be to find one with a lower lumen output, which is what I might do. The primary reason the resistor is used in the first place is to prevent blowing the fuses when you toggle high beams by pulling the stalk back. If you have an incandescent bulb in the dash, you could dim THAT by changing resistor values. I can't remember if the socket uses a 194 or a 168 bulb. They're the same dimensionally, but the 168 bulb is brighter and draws more current (also as a consequence, hotter). If the original design was for a 168 bulb, I would try a 194 bulb instead to see how you like it.
Well, a resistor worked. I messed around with bulb on my test bench power generator. At 14v unrestricited the LED pulls 0.019Amps. Swap over to constant current and reduced the amps until I found the brightness level i thought was about right, which was 0.003amps. Did the math to double check the superbrightleds specs and the LED has about 74ohm of resistance on it own. But anyways I end up ordering a 4K Ohm resistor from Mouser electronics. Threw it in today and it’s prefect. No more blinding myself with the hi beam indicator.


7A3AA90E-0359-4DCF-88B4-1EB50B4DF26E.jpeg
 
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Spook50

My daughter likes Stitch
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Well, a resistor worked. I messed around with bulb on my test bench power generator. At 14v unrestricited the LED pulls 0.019Amps. Swap over to constant current and reduced the amps until I found the brightness level i thought was about right, which was 0.003amps. Did the math to double check the superbrightleds specs and the LED has about 74ohm of resistance on it own. But anyways I end up ordering a 4K Ohm resistor from Mouser electronics. Threw it in today and it’s prefect. No more blinding myself with the hi beam indicator.


View attachment 2601508
I stand corrected. Looks like I need to church myself up on LED circuits again.
 

Seth S

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I stand corrected. Looks like I need to church myself up on LED circuits again.

i know there are dimmable LED bulbs now. And LEDs definitely have an on/off voltage threshold with minimal output difference regardless of applied voltage unlike an incandescent. But I know from personal experience that my LED headlamp light output does vary with the amount of charge remaining in its batteries. Still I think it’s a pretty small range of light output to voltage drop as compared to the older filament bulbs.
 
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i know there are dimmable LED bulbs now. And LEDs definitely have an on/off voltage threshold with minimal output difference regardless of applied voltage unlike an incandescent. But I know from personal experience that my LED headlamp light output does vary with the amount of charge remaining in its batteries. Still I think it’s a pretty small range of light output to voltage drop as compared to the older filament bulbs.
Yeah the bulb in question has a pretty generous volt spread, it's advertised as 10-16VDC. But with my test bench power supply on constant current the light was working all the way down to around 8.3 volts.
 

Spook50

My daughter likes Stitch
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i know there are dimmable LED bulbs now. And LEDs definitely have an on/off voltage threshold with minimal output difference regardless of applied voltage unlike an incandescent. But I know from personal experience that my LED headlamp light output does vary with the amount of charge remaining in its batteries. Still I think it’s a pretty small range of light output to voltage drop as compared to the older filament bulbs.
Yeah, that's what had gotten me was the availability of dimmable bulbs. Ironic that I have dimmable bulbs all over my house 😂
 

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