Question

what can cause solder to reflow and melt connection points on a starter? faulty ignition switch faulty internal magnets over cranking loose electrical connection from the battery to the starter

Explanation:

Over - cranking causes excessive current draw. This generates more heat than normal at the connection points. The heat can be sufficient to reflow solder and melt connection points on a starter. A faulty ignition switch mainly affects starting operation but not directly heat - up connection points to this extent. Faulty internal magnets impact the magnetic operation of the starter, not the soldering. A loose electrical connection from the battery to the starter may cause intermittent starting issues but not usually enough heat to melt solder through normal operation.

Answer:

Over cranking