You wont have to provide a seperate gound once you install the entire cluster into the dash because once you install the entire cluster, it will be grounded by the mounting bolts and nuts when you have it tightened up into the dash. FYI, I have received a slight tingle from not grounding it good when I was just testing it. Thats when I then used a separate wire with the alligator clips.
As far as the winding on coil, I would think this is normal for it to get warm since the voltage is going to that winding coil. I wish I knew for sure but thats my feeling bout that unless someone else on this forum has a better answer.
