I just had a go at something else — I hooked the spindle up to an older board and didn’t have this voltage draw issue.

At the same time I didn’t connect the switch connections as they go through a relay on an ardunio board.

I then hooked up the Pheonix board with a relay to switch the on/off.

Instead of 3v draw I only had 0.8 and could control the spindle with a better level of control. However the relays I used don’t have a low enough trigger voltage.

There is correlation between the switch on/off and the PMW/gnd which seems really strange.