Are you able to turn off the child control and make it stop?
Also when it starts rolling down can you stop it by using the driver switch in the up position?

 

I have not tried to turn on the child control to see if that stops it from happening. The two times it has done it has been in the middle of the night. We just wake up to see that it has rolled itself down sometime during the night. It is really odd. Pretty worrisome too knowing that it just does it all by itself. We can't trust it to lock stuff up in the vehicle because we never know when the window will just roll down.

 

Since there is still power on one of the two wires running to the defective window, even if the master control switch is unplugged, I am thinking that there might be another relay somewhere that is not working properly. Does anyone know if there is another relay in the dash of the vehicle? I am totally stumped with this.

I was hoping that when I pulled the master control switch, the power would then be cut from the hot plug going to the defective window which would confirm the thought that the master control switch is bad and needs replacing. However, since the power is still present even when the master control switch is unplugged, I am not so sure that's my problem.:headbang::dunno:

 

Yikes I didn't know it was happening with the KEY off!!!
Any modifications to the vehicle? Stereo, amps, aftermarket GPS, anything like that.
Do all your windows still work with the key removed?

Sounds like something has been mis-wired or is shorting out giving it power all the time?

 

Yikes I didn't know it was happening with the KEY off!!!
Any modifications to the vehicle? Stereo, amps, aftermarket GPS, anything like that.
Do all your windows still work with the key removed?

Sounds like something has been mis-wired or is shorting out giving it power all the time?

Thanks for your reply funman1. I think I am getting closer to resolving the issue. I noticed that the kick panel area was wet so I pulled off the drivers side kick panel to inspect it closer. There is several electrical connector plugs behind the kick panel that were dripping wet with water. I dried them out with a hair dryer and found one of the plugs was a bit corroded. I cleaned it up with electrical contact cleaner and reinsalled everything. Everything now works as it should. I think the water was shorting the plugs out and the corrosian was effecting the rear window.

I did find that the drain in the sun roof on the drivers side was blocked at the entrance of the drain hole. I cleaned it out and tested it with a water hose to make sure it was draining properly and also checked to make sure no more water was coming into the vehicle. I did not see any sign of water coming in so hopefully that solved the issue. I also drenched the windshield and wiper area just to make sure the water wasn't coming in from that area. So far so good. Guess time will tell when the next rain storm comes along.

I still find it hard to believe that the clogged drain hole in the sun roof could cause it to leak into the vehicle in the kick panel area. Does anyone have any idea how that can happen?

 

I have a 2005 Highlander and when it gets wet outside, often the rear window will go down on it own and I can not get it to go back up.

What was your solution?

 

Here is what I found out. The water drain holes from the sunroof get plugged up with leaves and stuff. The water has nowhere to go but under the dash where it reeks havoc on the electrical system and caused my windows to roll down. I cleaned out the drain holes, dried out the car and it never happened again.