OK, try this out on the driver power window; basic testing 101.
Set your meter for DC VOLTS.
On the back of the driver window switch (where the wires go in) poke the meter red lead into the connector, touching light blue black wire's terminal (leave it here for now).
Ignition switch ON.
Now touch the meter black lead to bare metal (like a bolt head). Meter reads 12 volts = pass.
Take the meter black lead and touch:
Switch black wire terminal. Meter reads 12 volts = pass.
Switch yellow wire terminal. Meter reads 12 volts = pass.
Switch red wire terminal. Meter reads 12 volts = pass.
Now remove the meter red lead from the light blue/black, and poke into the connector to touch the red or yellow wire terminal (take your pick; these are the two wires going to the window motor).
Take the meter black lead and poke into remaining other wire terminal, red or yellow (i.e. the one not used in the previous step). Your meter is now connected between the two window motor wires.
Work the driver switch up, then down. The meter should show (as a pass condition) plus voltage one way, negative voltage the other direction (look for a "-" in front of the number).
>>> If you unplug the motor, the meter will show a full @ 12 volts; if the motor is plugged in, the voltage is usually less (but the motor will also be turning).
Any step failing, shows the problem area.
Hopefully these steps will make some sense to you- we've just tested power into the switch, tested ground into the switch, tested both motor grounds out of the switch, and then finally tested the switch operation in both working conditions.
Don't forget to turn ignition back off : )