1987-1993 Mercury Mariner Outboards 70/75/80/90/100/115HP 3 and 4-cylinder Factory Service Manual, Page 48Get this manual
Rectifier Test WARNING Disconnect battery leads from battery before testing rectifier
07300TerminalTerminalTerminalStator TerminalsPositive TerminalGround
NOTE: Rectifier can be tested without removing from engine1Disconnect all wires from terminals on rectifier2Use an ohmmeter (R 1000 scale) and perform the following testRefer to illustration for rectifier terminal identification
Rectifier Test
Connect RED meter lead to ground, BLACK lead alternately to terminals "a" and "c"Continuity IndicatedConnect BLACK meter lead to ground, RED lead alternately to terminals "a" and "c"No Continuity IndicatedConnect BLACK meter lead to terminal "b", RED lead alternately to terminals "a" and "c"No Continuity IndicatedConnect BLACK meter lead to ground, RED lead alternately to terminals "a" and "c"