harness plug getting hot

I'm very interested in what answers you receive, since I have a issue that is somewhat similar. When I drive my car for more than 15 minutes, the steering column near the ignition switch warms up more than normal. I have the optional factory light package with the time delay for lighting up the area near the ignition switch.

At each end, where do the steering column ground wire attach and connects occur ---on the steering column?, and on the firewall? where is the ground established?