Bombardier SeaDoo 1990 factory shop manual, Page 128Get this manual
Sub-section 05
Section ELECTRICAL (CDICHARGIING SYSTEMS)
IGNITION MODULE DIIODE (SCR1 TEST (4-5P ONLY)
AFTER THIE START SWITCH HAS BEEN DEPRESSED
READING DOES NOT CHANGE
READING IS AT THE CORRECT VALUE
READlINlG CHANGES, BUT IIT IIS LOWER THAN THE CORRECT VALUE
IGNITION MODULE DIODE (SCR) IS OPEN-CIRCUITED