Question

which cable is installed first when using the jump pack on a negatively grounded system?
either - no difference
depends on battery size
positive
negative

Explanation:

When using a jump - pack on a negatively grounded system, the positive cable is installed first. This is to prevent accidental short - circuiting. If the negative cable were installed first, connecting the positive cable could cause a spark if it accidentally touches a metal part of the vehicle (since the vehicle's metal is connected to the negative terminal in a negatively grounded system).

Answer:

Positive