1985 Ski-Doo snowmobile Service Manual, Page 379Get this manual
Section 04 ELECTRICAL Sub-section 06 (TESTING PROCEDURE)
CONTROL UNIT DIODE TEST (4-5P only)
AFTER THE START SWITCH HAS BEEN DEPRESSED
READING DOES NOT CHANGE READING IS AT THE CORRECT VALUE READING CHANGES, BUT IT IS LOWER THAN THE CORRECT VALUE