B250 3/4 Ton Van L6-225 3.7L (1984)
Power Window Switch: Testing and Inspection
Remove both power window switches from their trim panels and remove the wiring harness from the back of each switch. Turn the ignition switch to the
"run" position. Check for power and ground by connecting a test light between the TN and WT wires at the left switch harness and between the TN wire
and ground of the right switch harness. If the test light does not illuminate or is dim, check the circuit breaker, relay, and wiring to the switch.
Power Window Switch Test
To test left switch function, connect jumper wires as shown to the right switch harness. Connect jumper wires as shown to the left switch harness forcing
the windows to operate in each direction. If the window motors operate properly, the left switch is defective. If the window motors do not operate
properly, the window motors or wiring may be defective.
To test the right switch function, connect a jumper wire between the WT and VT wires of the left window switch. Now connect a jumper wire between
the TN and PK wires of the right window switch. The right window should move down. Disconnect the jumper wires and connect a jumper wire between
the WT and PK wires at the left window switch. Now connect a jumper wire between the TN and VT wires of the right window switch. The right
window should go up. If the window operates properly, the right window switch is defective. If the window does not operate properly, the window motor
or wiring may be defective.