CR-10 Ignoring Z-Stop Switch, Keeps Trying to Lower
I had this same issue with my CR-10s. My black and white wires were reversed where I plugged them in to the motherboard in place of the stock z stop wires. I had to take apart the connector and swap them, as they came backwards from the mfg. Once I did that it worked perfectly.

The image I'm attaching helped me solve my issue. It is not mine, after much searching I found kenneycp's reply on this comment thread 
https://www.thingiverse.com/thing:2975949/comments