must have lost it's ground but what your saying on the not turning over sounds like starter may be checked out and also the pos cable was caroaded up that means your alt is puting out more amps than the battery can take. have you took this to autozone and have battery and starter checked? because when you turn starter over it takes power away from fuel pump so have that checked also to see how much psi running on pump.. but if it isn't turning over it has lost it's ground to the motor and make sure your getting power from pos. sounds to me like it's starter or ground to the motor..good luck..