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Amber running light conversion

324K views 1.1K replies 303 participants last post by  cbdane  
#1 ·
I decided to start this new thread to show my latest results on experimenting with converting the amber LED front turn signals to running lights. As was originally discussed on this thread http://www.k1600forum.com/forum/bmw-k1600-tech-performance-chat/3296-running-lights.html I proposed that this could be a straightforward mod using a small circuit that essentially inverts the on and off for the lights. They would be normally on and then flash off when signaling. The turn signals have a 50% duty cycle when flashing, making their appearance unchanged when flashing but they will normally stay on when not signalling to improve overall visibility. This can only be done on the front since amber running lights aren't legal on the rear in the US.

I came up with a straightforward design using surface mount components. I noticed that the low voltage signal to the LEDs wasn't held at full ground so I used an optical isolator to uncouple the operation of the new circuit from the flasher control on the bike. A 1 watt resistor simulates the load of the LEDs so the bike won't report any faults. The proposed design uses four resistors, an optical isolator, and a mosFET switch. The picture below (first posted on the original thread) shows a test layout of the actual components on a paper template.

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The final version of the circuit board is only 0.4 x 1.0" (10 x 25mm) as seen below. There are three pairs of wires that need to be connected: to the signal lights, to the bike, and 0V/12V from a switched power source on the bike. The power source is needed since the bike normally only supplies voltage to the indicators during the on cycle when blinking. I connected the new signal boards to a spare 5A channel on my PDM60 that I recently installed which is also used to power a set of Clearwater Glenda lights. See more here: http://www.k1600forum.com/forum/bmw...orum/bmw-k1600-accessories/3076-pdm60-accessory-outlets-clearwater-glendas.html

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I didn't want to cut into the stock harness so I ordered male and female OEM plugs from BMW to match those on the LED indicator lights. These are quite pricey and are by far the most expensive part of the project. It took a couple of weeks for them to come in. The result, though, is a short cable containing the circuit that simply plugs between the lights and bike; neat and tidy. An initial mockup of the connectors is shown below.

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Once assembled, I sealed up the circuit board in a length of heavy duty waterproof adhesive-lined shrink tubing as shown below. In this photo, the circuit is ready to be installed and tested. Before doing so, however, I enclosed the red and black power wires in braided sleeving for protection.

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The next two photos show the circuits installed on the right and left sides of the bike. You'll notice that on the left side I went with a lead on one end that was a few inches longer to easily reach the stock connector without straining any connections.

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The pictures were just snapped with my iPhone but I think you can see enough to get the idea of how the circuits went in. You'll notice my Stebel Magnum horn upgrade described here: http://www.k1600forum.com/forum/bmw...k1600-accessories/940-k1600gtl-stebel-magnum-horn-installation-4.html#post16686

I like the approach using the OEM connectors for this running light conversion because it's not a permanent commitment and I could remove them from the lights very easily if it were ever necessary to do so.

Here's a quick demo of the running lights in action. No surprises here; they worked just as expected right out of the box. In the video, I first run through a series of turn signal indicator cycles before the modification. I then repeat the demo with the new running light circuits installed. You'll notice that I have the Clearwater Glendas turned all the way down so they don't blind the camera. Notice how they flash to full brightness when I blip the high beams. See what you think.

 

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#3 ·
#33 ·
They need to be connected to a switched source of power. Since both turn signals, together, draw less than 1A of current, I'm pretty sure that you could just piggy back them onto the low beam circuit (connector behind the left speaker). If you have an add-on fuseblock or a PDM60 (power distribution module), that's a great place to hook them up as well.
 
#12 ·
I’m continually amazed at the talent on this forum. Great work cbdane. :gm I gotta get me some of those. When it comes to electricity, I have to call in a professional when a light bulb blows so the tutorial is way over my head. Please put me on the list (if there is one).

So, materials are about $100. If I add the cost of labor for a laser scientist, that should put the price tag at about $2,500? :eek: :D
 
#34 ·
Count me in too. Would it be possible to link in the roundel lights so they will be running lights and turn signal lights as well?
No problem. The output transistor that I'm using is good for 5A which is about 10X more than the turn signals need. It would even drive a set of incandescent indicator lights on an older bike. Adding the roundels to the circuit would be just fine.