2026-01-29 JST-EH Extension Cable Wiring Fix¶

Warning

This page is translated by LLM and may contain some inaccuracies. 中文版 (Chinese Version)

This document records the process of fixing the JST-EH extension cable wiring error on 2026/01/23.

Background¶

The official BOM requires us to purchase JST-EH Cables and Housings. However, spending around 40 TWD for a single 3-pin JST-EH extension cable is not cost-effective, so I tried purchasing pre-crimped wires.

However, as shown in the image, if we name the pins 1, 2, and 3, there are theoretically two ways to connect them. Unfortunately, we bought the 1-3’ 2-2’ 3-1’ type, but Dynamixel requires 1-1’ 2-2’ 3-3’.

Solution¶

If you don’t want to repurchase, you have to find a way to back out pins 1 & 3 from one end and re-insert them correctly. Here is our method—I was sitting on the floor at the time, but you might find a more elegant way.

Hold the plastic connector housing on one end.
Step on the wire connected to pin 3 to fix it (or secure it in another way), leaving the other two loose.
Pull the plastic housing towards you while gently prying the rightmost plastic tab with a flathead screwdriver.
- Be careful not to use too much force, or the plastic might deform, affecting its ability to lock the terminal again.
- If successful, you can pull the wire out along with the metal terminal.
Do the same for pin 1.
Insert the wires back in the correct order. Ta-da! Done!