T100 SR5 Extra Cab Pickup 4WD V6-3.4L (5VZ-FE) (1998)
Four Wheel Drive Indicator Lamp: Testing and Inspection
INSPECT 4WD INDICATOR LIGHT
a. Disconnect the connector from the 4WD indicator switch Connect the switch terminal 2 and body ground.
b. Turn the ignition switch on. Check that the bulb lights up.
If operation is not as specified, remove and test the bulb.
INSPECT 4WD INDICATOR SWITCH
a. Check that the there is continuity when the switch pin is pushed.
b. Check that there is no continuity when the switch is free.
If operation is not as specified, replace the switch.