Rear window in-op but motor works

[tystaco]

So my 2000 limited rear window stopped working last week. It worked earlier in the day, I got a car wash, and now it won't work. When you press the button, you can hear buzzing like it is trying to work, but the window does not move.

I have read about the rear window wiper not seating properly, I have cycled that and made sure it is in the cradle, still no worky. I have pulled off the motor and tested it, works fine in both directions. I have 12V power getting to the motor plug.

The only thing I can think is the Power Relay has gone bad? It makes the buzzing noise you can hear in the video below when connected to the motor. When I disconnect the motor's power plug, the relay simply makes a single click each time the window button is pressed.

https://www.youtube.com/watch?v=lSkpBf7I0ms

 

[tystaco]

I guess I'll pull the relay out of my 99 and try it in the 00 to see if this is the issue...

Open to other ideas...

 

[kgriff]

Does sound like you might have a bad relay. Seems like swapping with your 99 is the simplest path forward at this point.

 

[tystaco]

Doesn't appear to be the rear ECU as I swapped my 99 into the 00 and it made the same noise, the 00's ECU ran my 99 just fine.
[MENTION=10169]TheDurk[/MENTION], I think I read quite a few responses from you about the rear window issues. Any ideas?

I am not sure if I would cause myself any problems if I pulled the motor and tried to move the window gears with a screwdriver? Is it possible the motor has gotten too weak to operate the mechanism?

 

[RAD4Runner]

ECU?
You mean relay?

Got multi-meter? Got schematic?

https://www.youtube.com/watch?v=lSkpBf7I0ms

While it's doing that, probe the motor power leads for voltage to see id you're getting anything there.

...
I have read about the rear window wiper not seating properly, I have cycled that and made sure it is in the cradle, still no worky. ...

Usually the wiper park switch will ground the wiper control relay input IF the wiper is not parked properly. At least on our first-gens.
Try disconnecting the connector to the rear wiper system. That should absolutely eliminate doubt on the wiper part/retract switch.

 

[tystaco]

[MENTION=80771]RAD4Runner[/MENTION], by ECU, I did mean the rear power window relay. I have 12V getting to the motor when the window switch is depressed and the relay is making the noise shown in the video... I would think if it was a wiper issue, the motor should be getting no juice sent to it?

Is there a good way to disconnect the wiper part you discussed? I will try and hunt around.

 

[tystaco]

Disconnected the plug that went to the rear wiper, I assume (can't see due to the metal shield blocking the wiper motor) that would disconnect the wiper disconnect. Still had the same issue trying to run it with the wiper unplugged.

 

[RAD4Runner]

From above^^^, my guess [not as good as yours] is you disconnected the correct part to isolate the wiper park switch.

... you can hear buzzing ... I have pulled off the motor and tested it, works fine in both directions. ...
The only thing I can think is the Power Relay has gone bad? It makes the buzzing noise you can hear in the video

When I disconnect the motor's power plug, the relay simply makes a single click each time the window button is pressed.

Is it possible the motor has gotten too weak to operate the mechanism?

[MENTION=80771]RAD4Runner[/MENTION]... I have 12V getting to the motor when the window switch is depressed and the relay is making the noise shown in the video... I would think if it was a wiper issue, the motor should be getting no juice sent to it?.

The relay is buzzing but do you sense anything about the motor while you're trying to do that?
IF you are getting power to the motor, yes, it's possible that it is weak, or that there is mechanical resistance to the motor. Moisture/humidity sometimes makes the glass stick to the track.

Tried pulling the motor out so there is no mechanical load, but connecting like normal to see if motor would turn?

 

[tystaco]

Tried pulling the motor out so there is no mechanical load, but connecting like normal to see if motor would turn?

That is my plan today. Pull the motor off of the window gear and see if it works in the system without load. I had pulled it off and tested it directly to the battery, but I need to eliminate the possibility.

Does anybody know if you can manipulate the window manually? I am really hoping this is something mechanical, since motors and relays, for new OEM, are all $300+ (I'd get a used unit, but still).

 

[tystaco]

Here is the video showing the results of pulling the motor off the window gear. It works, but it is jerky.

https://www.youtube.com/watch?v=QrdU3n8Cgdo

I then cleaned the tracks and greased them, operating the window up and down by turning the gears with a screw driver. I then ran the window with the motor on it and had the same results as before... However, I did help the window down while running the motor, so I am heavily leaning towards a weak motor...

 

[tystaco]

Solved

For anyone that finds this in the future, my issue too turned out to be a bad ground between the hatch and main body. The wire was not fully split, so I would get 12V and ground at the motor, but once under load it would go to ground.

 

[RAD4Runner]

...The wire was not fully split, so I would get 12V and ground at the motor, but once under load it would go to ground.

Hmmmm.... How do you fully split a ground wire?
How would a ground wire get 12V at one time and then ground at another?
Care to share picture to help others in the future?

 

[tystaco]

Hmmmm.... How do you fully split a ground wire?
How would a ground wire get 12V at one time and then ground at another?
Care to share picture to help others in the future?

[MENTION=80771]RAD4Runner[/MENTION], I actually tossed in the towel on this after running out of time/patience and took it to my mechanic. So I likely messed up the interpretation, but he did say that there were still a few strands of wire intact and that there was 12V and ground at the motor.

I need to work on my electrically savvy.

The symptoms may have been constant, not like what I described about once under load it would go to ground. Looking back at my videos, it confused me why the motor was so jerky, and not a smooth rotation. I assume that this was due to shorting?

 

[RAD4Runner]

[MENTION=80771]RAD4Runner[/MENTION]...So I likely messed up the interpretation, but he did say that there were still a few strands of wire intact and that there was 12V and ground at the motor....

Ok makes sense. ONLY strands of wires left makes sense. Wire severed to a few strands left causes that wire to have high resistance. When there is no load, you get close to 12V. When there is current running through the strands of wire, the resistance will cause voltage downstream from where the cut is to go down, resistance of the wires left also causes it to heat up and further increases the resistance and the voltage drop so V could actually start to approach zero OR near ground.