[damnyankee36]

The radio is grounded through the brackets and I think the speaker is also grounded to the body electrically, but not directly. If it is grounded it's through the radio/speaker harness. Here's a photo of the harness.

The speaker wires are permanently attached to the speaker and its 3-terminal connector plugs into the back of the radio. The red power wire plugs into this same connector and the other end connects to the fuse box to the left of the "RADIO" fuse.