Need radio wiring help for a 1989 Dodge Caravan

I am trying to install a pioneer stereo into an '89 Dodge Caravan. I am making my own wiring harnesses using the old radio connectors (which I have removed from the OEM radio's circuit board). My two main questions are:

1. Where should I ground the new stereo? (The old radio had a flat braided metal cord bolted to the back of the OEM stereo housing. I suspect this is the grounding cord, but don't want to just assume that.)
   
2. Is there a site where can I get a free radio wiring diagram, specific to the '89 Caravan; or someone who can answer some other specific questions for me?
   

I have the installation manual for the pioneer unit, and a generic wiring diagram for Dodge Caravans (from the 1984-1995 Haynes manual), but I have seen other wiring diagrams online specific to the '89 Caravan that have conflicting information.

Please help!