You do not mention what year you have.

Enough 240s are similar that I'll hazard a guess.

The electrical box is the ICM, ignition control module, a computer that controls spark advance.

The wire you speak of, is it rather fat, and starts out connected to a vacuum thing on the ICM near the bottom of it? If so, that is a nylon tube, not a wire. It connects to the intake manifold and feeds manifold vacuum to the ICM. It is important. Without it you should note poor acceleration and power.

Look for a fitting on the intake manifold that has a rubber elbow on it, and that nylon tube goes on the other end. The sides of the elbow are about 1-inch. From the intake manifold it points forward and the 90 degree bend points downward. The nylon tube comes up vertically to connect.

Good Luck,

Bob

:>)