2004 toyota sienna

The passenger side switch may be bad, stuck is down position but for master switch not working it I suspect a fuse or short. Route the master switch passenger side button to another window and see if it works on that window or use a multimeter to see if power is going out when button is used both ways.

thanks for the quick reply, Engine Creator. i was gonna swap switches but thought they weren't compatible, but i realize now i should be able to disassemble the button from the master switch assembly and check that way, right? i've also tried my hand with the multimeter but am not confident i'm finding ground, (for example when i tested resistance, it stayed at 1.) btw, when they say "Body ground", am i best off connecting to the car battery to ensure the most reliable results? thanks again.

I think you can do it there in the master switches. Disconnect that passenger button in master and another known good button and connect the passenger window wires to it and if it operates then that passenger button in master is bad or if it fails to work then search elsewhere for problem. If connectors do not match up run jumpers. Also in ohms on voltmeter at master switch check each passenger button wire all the way to motor and or switch over on passenger side door, check each wire and put leads on the same wire, does not mater which end you put positive or negative just go from one end to the other may have to disconnect them too since that switch over there is stuck on down and see if there is high resistance indicating a short in it somewhere. (Voltmeter) in volts mode DC ground to Battery if you can or by jumper wire from battery, should be also main ground wire in the harness to switches too but hard to say which unless you see a solid black or brown without a stripe, the button completes the circuit to operate the motor, which can do this by a live or ground wire depends on how its wired. Body should be fine unless a wire is shorted on it, which you may have figured something out there, you can put negative voltmeter to battery ground terminal and positive to body, engine and/or frame in volts DC if any reading appears there is a short to ground somewhere shorting.

And for another note while those are hooked up in the above check for short to ground if no reading you may have to have someone turn stuff on and off to see if a reading develops. and on the check above test on ohms for resistance on pass wires do each wire for this test that goes from button to passenger side door motor may have to unhook motor too from one end of wire to the other.

One thing I'd add, that might be helpful, is that I believe the local switch is critical for the window working correctly. I was working on my 2004 Toyota Sienna sliding door and had removed the local switch and attempted to roll up the window from a remote switch, but it would not roll up at all until I reinstalled the local switch.

Engine Creator ...thanks again for your contributions. it looks like the connections won't match so i'll have to hook up those jumpers. i'm guessing they'll have alligator clips on both ends? please clarify when you say, "put leads on the same wire". do you mean on the wiring harness? if so, which wire? regarding ground, the diagram says ...To Power Window Master Switch (Ground) R-L 5 SU and To Power Window Master Switch (Ground) B-W 2 SD. i assume this means Switch Up and Switch Down. so, can i use either of those wires for ground rather than running cables from the car battery? finally, when you say "you can put negative voltmeter to battery ground terminal and positive to body", please explain. i thought body meant ground. sorry for all the questions.

John...thanks for that tip. i suppose that's what they mean by "wired in parallel". i was wondering the same thing, but when i was performing tests with the multimeter, they would have me disconnect switches, harnesses, etc., so i wasn't quite sure if it mattered anymore.

what i'm thinking now is -- if we're all in agreement -- i might want to try to clean out the passenger switch (or buy a new one) to get that "unstuck" so i can get the passenger side to work right. then with that variable out of the way, troubleshoot the driver side master switch. make sense?

When checking resistance you check one wire, at each end just to rule out a short. I would disconnect the wire being tested from both ends, you can do this test on the switches to see it open and close or if its not opening or closing.