The rectifier is what changes your AC current into DC current. Your regulator adjusts that current to maintain 14 VDC.
If you want to test it, start the PWC, take a multi meter and test the battery. If your getting 14 VDC on your multi meter at the battery, then the rectifier is good....
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Seadoosnipe......forum mechanic and moderator
when i tested mine the voltage ran low but I forget exactly how low. Hopefully that is the answer because it is a do-it-yourself that is not too expensive