For the life of me I cannot see how a compensator has anything to do with a rectifier. The components of the charging system are the rotor, stator and the rectifier. Any of those can fail. The rectifier is the easiest to replace as if is external to the engine. The rotor and stator are in the lower have of the engine and, unfortunately, between the engine and the compensator, so the engine must be pulled to replace them.
First step. Unhook the rectifier. Now check the voltage between the wires coming out of the engine (not to ground). You will need to look up what the voltage should be. If it meets spec it is not the rotor/stator but the rectifier. The cost of a rectifier is about $150 or so and it is plug and play.
