1999-2004 Honda TRX400EX FourTrax Service Manual, Page 247Get this manual
18LIGHTSSWITCHES SERVICE INFORMATION BULB REPLACEMENT IGNITION SWITCH 18-1 18-2 18-3 HANDLEBAR SWITCH CLUTCH SWITCH NEUTRAL SWITCH 18-4 18-4 18-5
SERVICE INFORMATION
GENERAL
A continuity test can be made with the switches installed on the vehicleAll plastic connectors have locking tabs that must be released before disconnecting, and must be aligned when reconnectingTo isolate an electrical failure, check the continuity of the electrical path through the partA continuity check can usually be made without removing the part from the vehicleSimply disconnect the connectors and connect continuity tester to the terminals or connections