Help... Another rear window won't work :/

[Smog-guy707]

Alright guys, here it goes. I need help troubleshooting why my window does
Not roll up or down.

I understand there are more than one fuse to check when it comes to the rear window. All of the fuses are ok, and my window lock button is not pressed.

My rear wiper and defogger work perfectly fine. When I press the switch up or down, there is a weird buzzing noise coming from the rear window control unit in the rear hatch. I thought it was awkward that a little unit makes a noise so I replace it with no luck

My rear hatch lock cylinder is kinda mest up, the lock cylinder is still there, however he small plastic price holding it in place broke, so it's just dangling there. Wonder if that has anything to do with it.

Window will not work with the remote, if I use the lock cylinder in the back, or the button

So I tried disconnecting The rear window motor and jumped power and ground directly at the motor and, voilà the winow will go up and down without hesitation, which means the motor and regulator are working just fine

I checked for voltage present ad the harness side of the motor and found battery voltage present at the motor when the up or down button is pressed

I know it possible I may have gotten a defective rear window cpu, the replacement I put in makes the same noise as my old one :/

Any input is appreciated, I'd really like to use the rear window function

 

[IBallEngineer]

Alright guys, here it goes. I need help troubleshooting why my window does
Not roll up or down.

I understand there are more than one fuse to check when it comes to the rear window. All of the fuses are ok, and my window lock button is not pressed.

My rear wiper and defogger work perfectly fine. When I press the switch up or down, there is a weird buzzing noise coming from the rear window control unit in the rear hatch. I thought it was awkward that a little unit makes a noise so I replace it with no luck

My rear hatch lock cylinder is kinda mest up, the lock cylinder is still there, however he small plastic price holding it in place broke, so it's just dangling there. Wonder if that has anything to do with it.

Window will not work with the remote, if I use the lock cylinder in the back, or the button

So I tried disconnecting The rear window motor and jumped power and ground directly at the motor and, voilà the winow will go up and down without hesitation, which means the motor and regulator are working just fine

I checked for voltage present ad the harness side of the motor and found battery voltage present at the motor when the up or down button is pressed

I know it possible I may have gotten a defective rear window cpu, the replacement I put in makes the same noise as my old one :/

Any input is appreciated, I'd really like to use the rear window function

OK, so if you have voltage with the switch depressed at the motor(and I'm assuming it switches positive from the Green for up and Red for down), Then what you don't have is ground. Ground is also provided by the Back Door ECU. If terminal 26 on the back door ECU has a good ground, and the 12V sides switche correctly, it's a faulty ECU. But first check to see if it is providing power and ground in either direction when the switch is applied.

 

[Smog-guy707]

i will check that pin for ground tomorrow thank you very much

So i probed the motor wire that comes from the ecu, and voltage when the switch is pressed is only about 5 or 6 volts? if i disconect the motor... i get battery voltage at the same location



ecu makes weird noise and only about 5 v present when pressing the switch.

 

[Smog-guy707]

disconnected



what am i missing here?

 

[AZ4Running]

Hey a power probe. I love mine use it all the time. Sou ds like you have a a possible short to ground causing the drop or the motor is bad. Using the power probe as a swith connect the ground (little wire with gator clip) to one of the pins on the power motor and one the other pin use the pointy tip and apply battery voltage. If nothing happens the reverse the conections at the power motor pins. If the motor comes on and the window rolls up or down th3nyou have an issue elsewhere. If so the start by checking continuity of the wiring to the window motor. But with the info you have provided it sounds like a bad motor or interal short to gfround in the motor causing the power brop.
My rear wi dow does not work either so i feel your pain. But i have a differnt issue cause my rear wiper/washer and power lock dont work either

 

[Smog-guy707]

OK, so if you have voltage with the switch depressed at the motor(and I'm assuming it switches positive from the Green for up and Red for down), Then what you don't have is ground. Ground is also provided by the Back Door ECU. If terminal 26 on the back door ECU has a good ground, and the 12V sides switche correctly, it's a faulty ECU. But first check to see if it is providing power and ground in either direction when the switch is applied.

Thank you so much. because of your help I was able to troubleshoot my issue

Here is my fix in case anyone ever runs into the same problem

I check pin 26 at the back door ecu for Ground and got a very poor signal. My test light would barely light up.

I supplied ground myself by "T"ing into the black/white ground wire that comes out of the small cpu and put it on a known good ground. The window now rolls up and down

Removed the 10 pin connector in the back hatch and sure enough it had a bad contact on that ground pin.

Happy camper now thanks guys

 

[IBallEngineer]

Thank you so much. because of your help I was able to troubleshoot my issue

Here is my fix in case anyone ever runs into the same problem

I check pin 26 at the back door ecu for Ground and got a very poor signal. My test light would barely light up.

I supplied ground myself by "T"ing into the black/white ground wire that comes out of the small cpu and put it on a known good ground. The window now rolls up and down

Removed the 10 pin connector in the back hatch and sure enough it had a bad contact on that ground pin.

Happy camper now thanks guys

You were pretty close by yourself, you just needed a little nudge. Always happy to see a problem solved.

:hail: