After Factory LED Lighting
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Joined: Nov 2009
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From: Virginia
After Factory LED Lighting
Hello
I'm looking at installing an off the shelf LED "brake, turn signal and running light strip system on my Helmet trunk. The package says it has a control circuit board and does not require a load equalizer because it is not replacing the exiting lights but adding a amp or 2 to the circuit.
Here is the best part, I want to do this on an 08 FXDC w/security. People just can't see me with the single puny light that comes on the bike! I may also convert the exiting lights over to LED later using a much more expensive conversion kit from HD.
Molson9
I'm looking at installing an off the shelf LED "brake, turn signal and running light strip system on my Helmet trunk. The package says it has a control circuit board and does not require a load equalizer because it is not replacing the exiting lights but adding a amp or 2 to the circuit.
Here is the best part, I want to do this on an 08 FXDC w/security. People just can't see me with the single puny light that comes on the bike! I may also convert the exiting lights over to LED later using a much more expensive conversion kit from HD.
Molson9
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From: Virginia
I was hoping one of the HD electrical guys would share some knowledge on how and why it is necessary to add resistance or a new turn signal controller to the wiring system to make the HD LED systems work correctly. My understanding is that there is some problem with the electrical system powering the LED's because it requires a load equalizer. I don't want to mess up my Bike. With that said I have done this to a car with out doing damage. Please help me understand LED's on Harleys....
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Joined: Nov 2007
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From: East of the Sun, West of the Moon
Molson9, it's not so much an issue with the electrical system as it is with the turn signal and securty modules (TSM or TSSM whatever your case may be). The TSM is looking for a very specific range of voltage/amperage returning from the lamps to the TSSM or TSM otherwise it will possibly trigger the ECM to throw a diagnostic code thinking the light(s) are burnt out and could possibly make the lights blink faster, slower, not at all, or even erractically. This is the best explanation of Motorcycle LEDs that I've found and it does come in handy from time to time as a reference.
http://www.customdynamics.com/led_mo...hting_faqs.htm
http://www.customdynamics.com/led_mo...hting_faqs.htm
3rd Gear
Joined: Dec 2011
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From: Boston
In the old days, you knew your brake light was burned out when your buddy told you it was... as they improved safety and features, HD added a circuit to monitor the current draw of various circuits (like the brake light) and trigger a warning light if they were too far off the expected amount.
That circuit is in the TSSM as mentioned.
As far as needing load balancers or resistors... that's easy enough to explain but a bit confusing. If you figure a circuit where power flows into the bulb then out and back to ground.... it will draw a certain amount of power. An LED works the same way, but draws less power. When you add a resistor, you add it in parallel with the LED's, so that when you hit your blinker, power flows through the LED and also through your resistor.
"but don't resistors reduce current". Yep... but for a given ohm value, if you put a voltage into a resistor you will get a current. A bike is around 12 volts, so based on the ohm value you can figure out the current that will flow through that resistor. When you hook it up in parallel with the LED, the total current flowing will be the amount going through the LED plus the amount going through the resistor. That's why the resistor gets it's own connection to the power and ground wires - so that it creates a second path for power to flow.
Getting technical.... if anyone took any electronics classes, Ohms law says V = I * R where V = volts, I = current and R = resistance. Watts is just volts times amps... so a stock 1157 bulb might be 25 watts, which is about 2.1 amps at 12 volts. So if you wanted to get a resistor that created the same current draw as a bulb did,
V = 12
I = 2
So R = V/I which is 12/2 which is 6 ohms. So a 6 ohm resistor connected to 12 volts will flow 2 amps, which is about the same as a stock 25-watt bulb.
Since your LED signal will also draw some power, you would want a little higher ohm rating... so maybe 8-10 ohms would be good.
One other thing to consider is power. A resistor flowing 2 amps at 12 volts is turning 24 watts of electrical energy into heat. If you connected a 1/2 watt resistor (the watt rating is the ability to dissipate power), it is going to way waaaay overheat trying to dissipate 24 watts. It could even catch fire or explode. So you want at *least* a 25 watt resistor, but a 50 would be better (since it has a higher limit, it won't get as hot dissipating 24 watts).
Hope this info helps someone.
That circuit is in the TSSM as mentioned.
As far as needing load balancers or resistors... that's easy enough to explain but a bit confusing. If you figure a circuit where power flows into the bulb then out and back to ground.... it will draw a certain amount of power. An LED works the same way, but draws less power. When you add a resistor, you add it in parallel with the LED's, so that when you hit your blinker, power flows through the LED and also through your resistor.
"but don't resistors reduce current". Yep... but for a given ohm value, if you put a voltage into a resistor you will get a current. A bike is around 12 volts, so based on the ohm value you can figure out the current that will flow through that resistor. When you hook it up in parallel with the LED, the total current flowing will be the amount going through the LED plus the amount going through the resistor. That's why the resistor gets it's own connection to the power and ground wires - so that it creates a second path for power to flow.
Getting technical.... if anyone took any electronics classes, Ohms law says V = I * R where V = volts, I = current and R = resistance. Watts is just volts times amps... so a stock 1157 bulb might be 25 watts, which is about 2.1 amps at 12 volts. So if you wanted to get a resistor that created the same current draw as a bulb did,
V = 12
I = 2
So R = V/I which is 12/2 which is 6 ohms. So a 6 ohm resistor connected to 12 volts will flow 2 amps, which is about the same as a stock 25-watt bulb.
Since your LED signal will also draw some power, you would want a little higher ohm rating... so maybe 8-10 ohms would be good.
One other thing to consider is power. A resistor flowing 2 amps at 12 volts is turning 24 watts of electrical energy into heat. If you connected a 1/2 watt resistor (the watt rating is the ability to dissipate power), it is going to way waaaay overheat trying to dissipate 24 watts. It could even catch fire or explode. So you want at *least* a 25 watt resistor, but a 50 would be better (since it has a higher limit, it won't get as hot dissipating 24 watts).
Hope this info helps someone.
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