2003 Ski-Doo ZX Series Factory Shop Manual, Page 290Get this manual
Section 06 ELECTRICAL Subsection 06 (TESTING PROCEDURE)
Ignition Switch (key, if equipped) Disconnect switch housingUsing multimeter, check between MAG and GRD terminals if the circuit is open (0.Lin operating position and if the circuit is closed (0in off positionEngine Cut-Out Switch All Models Unplug switch block connected to main wiring harnessCheck using multimeter by connecting probes to appropriate wiresRefer to corresponding IGNITION and ELECTRICAL SYSTEM TESTING table in this subsectionThe multimeter should indicate an open circuit (0.Lin operating position and if the circuit is closed (0in off positionNOTE: For the next step, no switch must be connected to the main wiring harnessDisconnect all switches from the main wiring harness and check the continuity of each wire by connecting probes to the end of wires of the same colorRepeat with all other wiresIt is important to mention that all wires of the same color within given harness are connected togetherThese wires should therefore have closed circuitOn the other hand, BLACK and BLACKYELLOW wires must have an open circuit (0.L )Repair or replace if necessary