Battery is fully charged and measures 12.56V across the battery posts. Measuring across the exposed terminals (the battery is down in the fender and not up top where most vehicles have them, and in lieu of that there is a positive terminal placed up top) shows only 2 - 3V. The vehicle appears to be completely dead. Absolutely no lights/sounds. Cannot even attempt to start it. If boosted the car starts right up and runs, as long as the cables remain connected. Once removed the car sputters and dies out unless the gas pedal is depressed. The car will run at a higher ram but it still flickers and a relay can be heard clicking back and forth. Where do I begin to troubleshoot?