1989 Ski-Doo Repair Manual, Page 394Get this manual
Section 04 ELECTRICAL Sub-section 05 (ELECTRIC STARTER)
Test armature for shorted winding: When the armature is rotated in the growler with steel strip (hock-sow blade) held obove it, the strip will vibrate over trwt area of the armature which has short circuited
A009 004 010
Check the dynamic brake winding for open circuit by placing one test probe on the positive brush and the other probe on the negative brushA009 004 009
Test the armature for open circuit: Use growler test probesPlace one test probe on commutator bar and the other test probe on the neighboring barRepeat this operation for all bars, moving one test probo at timeIf the growler lamp does not turn on, the armature circuit between these two (2) bars has an open circuitThe armature should be replaced or repaired; open circuits most often occur at the commutator riser where coils are soldered(Burnt commutator bars are usually an indication of an open-circuited armature coil