Trouble shoot window motor / wiring


#1

Problem: Toyota Sienna 1999 passenger side window won’t activate.

Driver side window works fine but passenger side window stopped working abruptly after removing door panel to work on exterior door handle. That was a few months ago - assumed reassembly was at fault, but let it go through winter. Neither window switch (driver side or passenger side) activates the passenger window.

Now it’s spring, windows should open, so removed door panel again: window switch connector was seated and locked into the harness, nothing visible to suggest problem on the connectors. Otherwise, nothing else looks amiss. Reconnected switch with door panel removed - no change.

With switch removed, a grounded test light shows 12 volts in the harness on the blue/yellow wire. There was nothing at any other harness contact.

Tried jumping between the blue/yellow and the other wires one by one. None activated the window. I don’t know how these work, and whether jumping this way, one by one, would power the window, but guessing all the connections must be complete for the window to move.

Since neither switch activates the window, I’m ruling out the switch. Since driver side window (and all other power items) work fine, ruling out fuse. Could be window motor, but the only apparent change was removing / replacing door panel. Prior to that, there was no sign that the motor was failing / laboring, etc. Passenger side door lock switch works. What am I missing?


#2

Make sure the motor is okay by applying power and ground directly to the motor wires. You may have to reverse the polarity of the connection if the widow is all the up. This is how the switches make the window go up or down, by reversing the polarity of the power. Power usually has to pass through the door switch for that door in order for either switch to work. Since you seem to have power getting into the door there may be a problem with the ground return side of the circuit. Check to see if power is getting to one of the motor leads with both switches. If you do see power then you may have a bad connection to ground. It could be in the door jam or in the driver side panel. The most likely spot for the trouble is the wiring in the passenger side door jam. Stress on the wires over the years by the door movement breaks the wires inside the insulation of the wires. There might be a replaceable harness inside the door jam.


#3

I think your test procedure is correct to bypass the switch. Jumping from the 12V wire to either of the other 2 completes the circuit to the widow motor to make it raise or lower depending on which wire has power. You didn’t however, check the power AT the motor itself. The wire should go from the switch to the motor, and carry power and maybe ground. Ground might be through the motor’s case or there might be a separate wire on the motor’s plug

Plug the switch in and probe the leads on the motor connector just to make sure its getting power and ground. If is has power and ground, plug the motor back in, hit the switch and whack the motor with a screwdriver. If the brushes are stuck, that may make the motor run. If not, replace the motor.


#4

The blue/yellow wire is the voltage supply to that window motor. The other wires ground the window motor for the up and down functions.

One thing to check is if the window lockout switch on the master control is turned on preventing the grounding of that motor.

If it’s not the lockout switch, then there’s a ground problem for that window motor.

Tester


#5

Bingo! Thanks @Tester. Problem solved.

I had a hunch that it was something simple which I was overlooking. No car I’ve owned previously had a window lockout switch, and I somehow hadn’t noticed that button - have only had the car a short time - & didn’t get the owners manual. Duhhhh.

Thanks also @Cougar, and @Mustangman for the good education. I was preparing to dive deeper into this if necessary, but I didn’t want to start hunting for a bad wire in the door jamb, or poking around on the motor contacts, until all the simpler things were eliminated.


#6

You’re welcome for the help. Thanks for the update.