Checking Rectifier Diodes

[mship]

1992 Evinrude 150 HP 60 Degree V6<br />I am almost sure my rectifier has gone bad (tach quit working, battery not charging) but before I trash it I would like to check the internal diodes. The stator checked out okay according to resistance readings per my manual, but my manual is unclear on the procedure for checking the diodes and I remembered reading on this forum about checking with a analog multimeter. Mine is water cooled with 5 wires coming out the top. yellow/red, yellow/gray, purple, gray, and red. Any help would be appreciated.

 

[wilde1j]

Re: Checking Rectifier Diodes

The diodes are potted. If bad, throw it away.<br /><br />To check functionality, ck for proper AC feed from stator. If that's OK, ck for DC voltage at battery terminals with motor running (usually expect 13.5 to 14.5 volts DC there. If the stator AC voltage to Rect/reg is OK and there is 12.7 VDC or less at batt terminals, the rectifier is bad ... replace. That's it!