Since the Ender 3 S1 does not come with a Z endstop preinstalled you will need to connect the included Z endstop cable that came with your Ender 3 S1 from the J713 header on the control board to the EZABL control board as shown in the pictures below.
Using our S1 Signal Cable Notes
NOTE the S1 Pro and Plus do not always come with a signal cable. We have a S1 version in our shop here: https://www.th3dstudio.com/product/ezabl-z-signal-cable-s1-version-ender-3-s1-ender-5-s1/
For our cable ONLY - The cable end with the wires in the 2 outer positions (Pins 1 and 3) goes to your printer control board. The other end with the 2 wires right next to eachother connects to our EZABL control board.
