Installing an LED lighting system by Francois Roux
From A to Z, the complete assembly description to make a LED light system including the 2-way blinking system. This set of pics shows you how to proceed for a simple assembly of LED light system including blinkers in one tail light. This is the assembly scheme.
This is the original glass light from a 1958 VW Beetle.
You need to use a copper pad for electronic assemblies that you'll reshape to match the glass light.
.The reshaped copper pad on the right.
I used an LED bulb for STOP and night lights that I resized.
You can see the future location: right in the middle of the copper pad.
You can see the hole for stop/night light in the middle. Now I positionned the LED for the blinkers. Now it seems fine. I always adjusted a pair number of LED lights for each blinker to make life easier in terms of current calculation and connection. Each light needs a current of 3V.
The whole assembly before welding
Little by little, the LEDs and resistors are connected independently from each side. Order is a must if you want to avoid shortcuts. You cannot destroy anything by doing mistake. It just work or not! Make some 'in between' checkings

When welding the LEDs on the copper pad, make sure to identify where are +/- poles are and order it the same way for each LED (eg: + on the left side). The LEDs are then welded on the pad. Then it's time to make the connection with the resistors and the LED itself. I used a 300 Ohms resistor per LED.

Testing the left side. Now the connections are OK, I wanted to avoid any future bad contacts with any metallic part of the body. I used a nail glaze to pour an "isolation layer " on the connections.
Same checkings with the electronic blinking relay
Connecting the stop/night light
The traditional relay doesn't work with LEDs due to lower electric consumption. I bought this electronic kit for EUR 10.
It works for tensions between 4.5-14V. You can also adjust the blinking frequency.
I used this blue plastic box to protect the small electronic device. This is a chewing gum box!
Back in the front light where all the electric connections are located on a CJ 750, I used a small screw driver to adjust the blinking frequency.
Tail light. Connections are done, and isolation as well.
The tail light back in place, left and right blinkers
One interesting thing to notice: The LEDs are polarised and you will need for the night/stop light to repolarised the source of the STOP light. I chose to reconnect it. It's easy and took me 5 minutes.