While you may have enough amperage to run dash lights and wipers you may not have enough "juice" to start the vehicle. I would pull the battery out and take it to your local auto parts store. They can test the health of your battery.
〉 Answered on Aug 7th, 2008 by Amanda J. Pierce, MBA "AJ", Certified Mechanic, Project Coordinator; Primavera Scheduler at VIGOR Alaska Industrial Shipyard & BizzM3ch Solutions