[petek]

Testing the coil is pretty easy. Disconnect from the box, attach a ground to one lead on the primary of the coil. Take a jumper from the other lead of the primary on the coil and touch it against the battery positive (briefly). If the coil is good the secondary of the coil will produce a spark.

Testing the full functionality of the box would be tougher ... but a simple test would be to watch your tachometer (as most tachs are attached to the box). If the tach is moving, then the box is sensing the rotation of the engine. Next, monitor the output of the box (across the leads that go to the coil). You should see the output changing (no output to +battery voltage) as the engine turns over.