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LED Turn Signal, Brake/Tail &running light conversion

82K views 227 replies 49 participants last post by  lhatl250 
#1 · (Edited)
In my quest for saving electrical power for running some of my favorite goodies, I decided to do an LED conversion.
I had changed my front signals in '88 to three wire turn/running lights so I
purchased two amber 1157 LED and two amber 1156 LED bulbs as well as a red 1157 LED for the tail/brake.

Converting the brake/tail was a simple plug and ply operation.
The signals was another issue. I changed out the flasher for an electronic one. Car Quest had one on the shelf. Simple plug and pay there.
Putting the rear 1156 in was also straight forward. Had I left the incandescent bulbs up front, I could have called it good right there. Putting the 1157 LED bulbs up front, I had the notorious four light flash. I had though about doing a two indicator system but decided to try an LED indicator bulb. A quick run up to Auto Zone for a pack of 194 LED bulbs solved the cross connection issue.



If I had the OE front signals it would have been finished but the 1157 LED bulbs threw me yet another curve. With the running lights the signals did not want to flash. They would modulate but not fully flash.
When I disconnected the wires for the front running lights there was no improvement. I noticed that if I grounded the running light wires from the front signals the signals would flash correctly.
That's all well and good but I like my front running lights.
After studying the schematic for the Rebel I decide to install a relay so I could have my running lights. I chose under the seat for the relay.
Radio Shack micro relay part number 275-241 looked to be a good choice. Tiny and robust it would tuck easily in to the area above the airbox under the seat. Soldering on the connections isn't for the faint of heart but the compact relay was worth the effort.


Putting a nice shrink wrap conduit with the two running light wires in it, the run along the main harness was very easy. I tapped in to the tail light circuit at the fender harness connection and also tapped in to both signals.
Powering the relay meant using the taps from both sides of the turn signal.
To prevent back feed and end up with the four flashing signal problem again, a pair of diodes for the relay power made for a quick and easy fix. I used 3 amp rectifier diodes from Radio Shack part number 276-1141 . They come two in a pack and two is what I needed.

When the signals are on, the relay connects the two running light wires to ground. The signals and indicator function just as they should.
When the signal is canceled, the relay switches back to the lower output front running lights powered by the tail light wire.


Since the 194 LED bulbs came in a two pack, I replaced the neutral indicator with the second one from from the pack.
The only downside with that is the amber 194 LED bulb in the neutral indicator is the amber shows through the green lens.
Still, that's livable.
The relay has a slight capacitance in its energizing coil, just enough so that it will stay latched during operation as long as the battery voltage and charging system voltage are at good.
One side effect of the relay is if battery voltage drops, the relay starts to click with the flasher blinking the opposite side running light.
I just figure I'll use that to judge my power draw when using heated gear! :D
 

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#4 ·
Thank Guba.
I got the urge while chasing down the tail/brake light gremlin that hit on the spring ride.
I should have thought it out a little more. I ordered from SuperBright and those are nice pieces. If I had thought about the indicator I would have ordered one from them in amber and another in green for the neutral. I should have also thought about the plate light, gauge light and high beam indicator, basically making everything LED except the headlight.

I don't know why the Powerlet stuff hasn't come n for you.
My local BMW dealer has a large display with all their stuff.
 
#5 ·
Powerlet stuff was sold by Crooked River Cycles, but they changed their name to Northern Ohio Ducati Triumph. As a result the Powerlet distributor needed them to open a new account. At least that's what they tell me.
 
#9 ·
I took some photos of the Relay installed under the seat.
The relay is covered in a bit of shrink tube to enhance its water resistance.
I did my best to stay with the Honda color coding.



I put a bit of hot glue on just to keep it in place and cut down on vibration.

 

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#10 ·
Grate writeup:thumb:
The relay is covered in a bit of shrink tube to enhance its water resistance
I would recommend Plasti Dip for that purpose. But shrink tubing works too. Was is the kind with glue on the inside?
 
#11 ·
No glue on the shrink tube, but I did seal the shrink with some hot glue.
I thought about Plasti-Dip but I don't have any on hand so I just rowed with the oars I had.
 
#12 ·
Anyone had any experience with the 'liquid electrical tape'? Saw it at homeless depot today and wondered if it would give any waterproofing qualities to a job like this...
 
#14 ·
My dad ordered some Plasti Dip from the US. As a spray. Its marked as "liquid electrical tape". Its clear.
Used some in the boat. Worked good in that environment.
 
#13 ·
Never used the liquid electrical tape, curious about it though.
It might be worth a try.
 
#16 · (Edited)
Update:
After some good riding, I noticed the cross connection issue start showing up again. It was very dim cross illumination and only happened when run at good rpm.
Essentially, its saving so much power that the batty was staying very topped up so the excess has to bleed off all that excess voltage, the LED indicator was reaching its breakdown point. Breakdown in a diode is where the voltage exceeds what the diode can stop. If the engine was shut off the lighting would return to normal. Rather than installing a parasitic resistance, I just decided to do a diode pack for the indicator light. I installed a pair of the same diodes that were used for the relay power circuit. Since those are rated 3 Amps at 50 Volts, they will not get near their breakdown point.

Also thought it would be a good to chart the electrical stuff that was added so I modified the wiring diagram to reflect my changes.
 

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#17 ·
LED part2. Rear turn now brake and tail, clear lenses

I have completed phase two of my LED conversion.
Replacing the sockets in the rear turn signals with dual contact sockets allowed for use of 1157 type LED bulbs. Replacing the amber 1156 LED bulbs with red 1157 LED bulbs is part of the process. The thing that really sets off the conversion is clear turn signal lenses. It turns out that K&S make clear lenses for the Rebel style turn signals. The K&S part number is 25-1070C.

This is how the look on the front

Here is how they look with the running lights lit.

Here is how they look on the rear.

I got mine from Dennis Kirk. Dennis Kirk part number is 210141.
Wiring the tail light part was very straight forward when use in conjunction with the previous LED running light conversion, just a single wire forward to the relay under the seat for the front running lights. With the previous LED conversion, tail light power could be easily tapped from the plate light wiring in the rear junction box.
Here they are lit as tail lights

Getting the turn signals to function as brake lights when not used a turn signals was a little trickier but not extremely difficult. Tapping in to the wiring junction under the front seat (behind the airbox where the main harness meets the rear fender harness) it a matter of unplugging the rear
wiring for the signals. The female bullet connectors are for the rear wiring, light blue wire for right, orange for left. The male bullet connector supply the power. Connecting a relay for each turn signal allows for tapping power from the brake light wire (green and yellow) to run to the normally closed side of the relay. Connect the power supply signal wire to the normally open side of the relay. Using a jumper from the signal power supply wore to the positive side of the relay's energizing coil and grounding the negative side allows the turn signal to self energize the relay coil. The only caution is that an electromechanical flasher MUST be used for all the relays to function properly. The electromechanical flasher add just the right amount of capacitance to the turn signal wiring to keep the relays latched during signal operation. Thermomechanical flashers (old style) would not function due to the low power draw of the LEDS. Fully electronic flasher would flash but not provide the capacitance in the circuit causing the relays to "flash" on and off, defeating the purpose of those relays.

With every light except the sealed H4656 halogen sealed beam and the corresponding high beam indicator in the rectangular bucket being LED, the power draw is just about 50 watts even with the added lighting, roughly 1/3 of OE lighting with incandescent bulbs.

The relays used for this wiring are the Radio Shack Model: 275-248
12V DC coil with 10 amp contacts. The 10 amp contacts provide plenty of head room for current through the signal wiring. Those relays with their compact size also got positioned under the seat.

I took some cell phone video of the lights in operation and concerted that to animated GIF. Hopefully that will load to show the rears in operation.
I'll show the modified schematic of the wiring diagram in any case.
 

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#18 ·
Unfortunately, the animation showing the signal in operation is too large to work.
Here is the wiring diagram that reflects all my current electrical modifications.
 

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#19 ·
Since I can't do the movie/gif, here are stills.
 

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#21 ·
Thanks Guba. With the low power draw of the LED lighting, might as well use them all for max visibility.

Recognize the location? I took the pics just about where your tent was at.
 
#23 ·
It got really green about a week or so after the trip. It happened almost overnight
 
#24 · (Edited)
With full compression and reduction in size, the animation was loadable to my album.
The flash rate in the video seems much faster than in real time. Almost like an antique moovie, the animation is almost cartoonish.
While its crude video, you can see the operation. as tail light all three work. When used as turn signals, the tail light on the opposite side turns off . During brake light operation, the opposite signal functions as an additional brake light.
 
#27 ·
Thanks Fridge!

Setting up the LED signals is pretty easy really. I just went full tilt because I could.
For those not wanting to do a diode pack on the dash indicator, it would be possible to use a three prong electronic or electromechanical flasher. The X terminal would get the black wire and the L terminal the gray. The third terminal marked P would just need a wire run up to the front junction box hooking to one side of the dash indicator and the other side would need to be grounded. I'll alter the wiring chart to show that setup and post it.

That Radio Shack relay would do the trick for the headlight. It is a SPDT relay or "changeover" relay and all you would need for the headlight is a SPST. Radio Shack carries those too but they are bigger. For the SPDT relay, just don't wire up the normally closed terminal.
 
#28 ·
The wiring chart for using a three terminal flasher with LED signals and keeping OE function on the dash indicator without using diodes.
 

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