2003 Ski-Doo ZX Series Factory Shop Manual, Page 99Get this manual
Section 03 TROUBLESHOOTING Subsection 05 (ELECTRICAL SYSTEM)
SYMPTOM CONDITION TESTINSPECTION
FALSE FUEL ANDOR TEMPERATURE GAUGE READINGSNORMAL USE1On fan-cooled models verify if gauge was connected on DC current by mistake (in case of optional installation)aFaulty installation of optional equipmentFind optional wires connected directly to DC ground (BK wire to chassis) or to any DC hot wire (RD, RDBU)Disconnect and reconnect to AC current (YL and YLBK wires)2Verify sender unit for free movement andor correct arm positionaDefective or damaged partCorrect or replace sender unit3Verify sender unitgauge wiring harness conditionaHeating, rotating or sharp part in contact with harnessImproper harness routingReplace or repair damaged wiresReroute where necessary