My old 1980 boat uses some kind of mercury racing ingition box for the 80,s It has the two trigger wires coming into it friom the Thunderbolt IV distributor, two wires goin out to the coil, a power wire and a ground wire. The timing module is built into the box. I have a no start condition on the engine that ran last yeaqr. I am not seeing spark at the coil when I crank it. I do have power and ground at the box. I swapped boxes from one engine to the other and still no start. My two other possibilites are a bad coil (which I can compare the ohm reading on it tommorow) OR the Thunderbolt pickup module went bad. Since its a hall effect sensor, how does one go about testing it with either a digital multimeter or even a small scope? This is the thumderbolt that has the studs on the side of the distributor body, not the flying leads.

https://bpi.ebasicpower.com/faq/MERCSB92-11.htm

Yup, that ^^^