I have tested stator and replaced rectifier after first charging issue. Ski charged fine for a couple of months and now blows 5amp fuse. Could it be Custer gauge or would more likely culprit be the black box?
Have you been "jump starting" the ski? It's been said that jump starting a seadoo causes a diode in the mpem to fail and short causing the 5amp fuse to immediately blow.
If you have soldering skills you should look into how to replace the diode.