That power is provided by the 25 amp circuit breaker that also powers up the rest of the windows. Does the rear window operate from the key cylinder in the rear gate?
I the other windows are working, this circuit diagram may help you as well to troubleshoot. You can download it and save to your computer AND make a printout to hold as you try to figure out the wiring.
Don't overlook the possibility of a broken wire inside the plastic covering where a wire is flexed as the door/tailgate is opened and closed flexing the wire every time. Outside can look good but inside has broken.
Good luck.
I see there are two power supplies from the fuse/relay block. One is ON when key is ON and other is HOT all the time. Not being familiar with Suburban, I am guessing that's so the key can operate the rear window without the truck's being turned on?
It looks like the HOT all the time line allows the window to be put up without the key in from inside the truck.
EDIT: I took another look and as I read the diagram, if you test for power at the plug for the motor you won't get any power, unless someone is operating a switch for UP or DOWN on the motor.
You might test the motor by applying power through a FUSE on a line from the battery and supplying a ground to the other contact. That will verify the motor does work.
These are difficult to understand the wiring diagrams on. I troubleshot the power windows on the scout troop van that was a middle 90s before their trip south years ago. It was the longest 2 days I spent in the _hour_ I was deciphering the colors and wires. Makes my head hurt.
Looking more at the circuits, if it doesn't go UP or Down from either cabin switch or the tailgate switch, that narrows down your problem area to that limit switch and motor or ground. Having two different power supply circuits helps diagnose. Note: I'm not an electrical engineer.
Answers
this circuit diagram may help you as well to troubleshoot.
You can download it and save to your computer AND make
a printout to hold as you try to figure out the wiring.
Don't overlook the possibility of a broken wire inside the
plastic covering where a wire is flexed as the door/tailgate
is opened and closed flexing the wire every time. Outside
can look good but inside has broken.
Good luck.
I see there are two power supplies from the fuse/relay block. One is
ON when key is ON and other is HOT all the time. Not being familiar
with Suburban, I am guessing that's so the key can operate the rear
window without the truck's being turned on?
It looks like the HOT all the time line allows the window to be put
up without the key in from inside the truck.
http://www.revbase.com/BBBMotor/Wd/DownloadPdf?id=49621
EDIT: I took another look and as I read the diagram, if you test
for power at the plug for the motor you won't get any power,
unless someone is operating a switch for UP or DOWN on the
motor.
You might test the motor by applying power through a FUSE on
a line from the battery and supplying a ground to the other contact.
That will verify the motor does work.
These are difficult to understand the wiring diagrams on.
I troubleshot the power windows on the
scout troop van that was a middle 90s before their trip south
years ago. It was
the longest 2 days I spent in the _hour_ I was deciphering the
colors and wires. Makes my head hurt.
2014 Malibu 2LT, 2015 Cruze 2LT,
2014 Malibu 2LT, 2015 Cruze 2LT,