can l test them with a c or d battery to see if they are my missing speaker wires

9 volt.

Go to ''installdr.com'' & click on the wiring schematic for Caravans.
Excellent site.

UPDATE at 7:45 PM - You might want to check behind the grille of ur ''nonworking'' speakers to be sure there is a speaker present. l thought my '90 Dodge Dynasty LE had six speakers two in the front doors, two in the rear doors & two on top of the dash, turned out there were no speakers on top of the dash but there were speaker grilles. l checked the wiring for the car & the two in the front doors & the two on top of the dash were the same so l had four front speakers.