Z-axis Heat Damage on Wire Terminal

Anyone experiencing issues with their Z-axis? I recently made the update on the stepper resolution to 2000ppr. Made several carves with no issues. I just fired it up tonight and the Z homing kept failing. It would send the axis down instead of towards home. Checked connections and condition of cabling. I did find obvious signs of heat on the green wire jumper inside the motor cover. I replaced this with a wire nut and it failed again. Did a reset and it homed fine. Doesn’t give me the warm feels though. The second time it failed during a carve and continued driving the bit down into my work piece when I tried homing. I had to shut the machine off and manually raise the spindle.