If the black wire is ground it's a silly, stupid thing to do. Black wires in in electrical and electronics should never he used for ground or neutral connections. If they had only made the wire green it would be a no brainer.
I am guessing it is the ground, but my gosh it cost no money to make the wire green. I never designed a controller using black for ground, but I have seen it hundreds of times. It still aggravates me.
Sending machines like this out to people that have no electrical or electronic knowledge, a DMM nor the ability to use one to trace circuits makes it even more important to use the correct colored wires. Black wires are live, at worst a switch leg in AC, and negative in DC circuits, so I would get clarification.
Last edited by dovetail_65; 09-23-2017 at 03:41 AM.