2004-2007 Honda Aquatrax ARX1200N3/T3/T3D Factory Service Manual, Page 481Get this manual
METERSWITCHES CIRCUIT INSPECTION Fit the safety lanyard clip to the base of the engine stop switchMeasure the voltage between the Yellowblue wire terminal (+) of the wire harness side connector and ground ()There should be battery voltageIf there is no voltage, check the following: open or short circuit in the Yellowblue wire between the ECM and off-throttle steering solenoid valve faulty off-throttle solenoid valve open circuit in the Blackred wire between the off-throttle steering solenoid valve and junction connector FUNCTION TEST Disconnect the vacuum hose from the check valve and connect the vacuum pump to the hoseDisconnect the vacuum hose from the off-throttle steering control diaphragmApply vacuum to the solenoid valveThe vacuum should be maintainedGround the Yellowblue wire terminal of the ECM 26P gray connectorFit the safety lanyard clip to the base of the engine stop switchThe vacuum should be releasedVACUUM PUMP CHECK VALVE ECM 26P GRAY CONNECTOR (viewed from the terminal side)