Installation of LEDs for upper front lights

I have 2 mm dia “cannon” LEDs. I first thought of inserting them directly at the lantern location, but this is impossible because the hole is too close to the roof. We’ll therefore have to use the light guides provided, cutting their vertical part, removing as little material as possible from the horizontal part, and polishing the section as best as possible.

Then we prepare the LEDs by folding their wires as in the pictures. On the left side, there are two free holes on the PCB that will allow the LED to be soldered with its 4.7 kΩ resistor (this value depends on the type of LED used). On the other side, we’ll have to drill dia. 0.8 mm holes.

You may have noticed that the connection between LED and resistor is done to the original white LED terminals (between the blue and black wires). It is a solution that I chose, after checking nevertheless, considering that the new LED was a high luminosity one, and that it would not pose a problem of underpower. The more electrically correct solution was to connect this circuit before the 1 kΩ resistor, but it was materially more complicated.

Rear head light

Head light end 2

Be careful to calculate the bending length so that the LED barrel reaches about 1 mm from the light guide: neither too close nor too far.

Front head light

Head light end 1


  • The light guide does not guide anything at all; with its oblique parts mispositioned with respect to each other, the light rays cannot be reflected correctly, and this is visible: the lantern is illuminated only less than half! See what it would theoretically be possible to do by correcting the positions — remove about 0.75 mm of material — provided that the machined surface can be polished. Definitely, the guy who designed this was probably not feeling himself!

Optical correction

Warm white 2 mm dia. LED with resistor
ref. 305/10 - 3,80 € per 10 — price 2013
at Electron-Discount