You should ground the black ground wire on the Pioneer unit to a good clean solid ground point. One of the very best ground locations is under an existing bolt in either kick panel. The shield on the antenna coax cable will ground the radio, but it is not a very good ground, electronically speaking. It has higher resistance than chassis metal. Using the antenna for ground can cause dimming and blinking of the radio lights, engine noise and alternator whine, distorted output and in some cases no output at all. In your 2000 Dakota there should have been a silver colored braided grounding strap behind the radio location. At one time the strap was bolted to the back of the chassis of the original Dodge radio. You can use that strap as ground for the Pioneer, but the factory ground straps have been known to become contaminated over time and you eventually wind up with another bad ground problem. It's always best to ground to solid, clean, bare metal, whether you are talking about a radio, fog lights, amplifier, or any other electrical component.
Last edited by 01SilverCC; 12-04-2009 at 10:13 PM.