Passenger window has been flaky for a while - works, doesnt work, etc. (only from operation on driver side though). I just replaced the switch on the driver side - but it apparently was not the problem because it is still not working. So what is the best way to attack this? It works fine from the passenger side.

 

You've already done the diagnosis. It's not the drivers side switch, it's not the pass. side switch, it's not the motor, so what's left. Look at the connection and the wires. Get the wiring diagrams, if I recall correctly the current path goes through both switches then operating either switch.

 

I pulled the pass side switch connector and reseated it. Now it works. Odd, I guess the connector wasn't fully seated??? As to whether it will keep working....