Rear windows not operating properly

[Chevyman07]

eace:Rear windows can roll down but not up utilizing the switches in both rear doors. The main controls in the drivers door will roll them up and down. Wondering what the issue is. Have taken off panel and checked out wiring and it all looks good. Figured motors are still good since they are able to roll down. Thanks in advance,

 

[bladenbullet]

the motors are ok due to the fact that the master switch works them both ways....there is a possibility of a master switch concern or both dedicated (rr/lr) switches are bad causing this concern....there is also the possibility of a wiring concern....

all the window motors operate on dedicated wiring with no direct grounds...polarity is changed inside the switches in order for multiple switches to operate the same windows without conflict....for this to happen the master switch has to provide power and ground to and through the slave switches...i believe there are also relays in the rear switches on these vehicle which control where the power and grounds are coming from when master or dedicated switches are operated....

it sounds more complicated than it is but can get dicey if someone doesn't know what theyre doing....a few simple tests at the switches should reveal the problem...with a proper schematic someone should be able to do a relatively quick diagnostic...

when I taught my students power windows I thought they were going to have a stroke testing operation at the car...I bugged back window wiring and had them walking around with nervous ticks for a day...

the fact that 2 switches are acting up (have you tried the passenger front with its dedicated switch?) leads me to believe it could be a master switch concern....but it wouldn't be the first time 2 switches went bad at the same time or a common feed got messed up...

 

[rockenthebowtie]

What year is it ?

 

[Chevyman07]

its a 2007 chevy Tahoe LS. I have tried the passenger front main switch and it works both ways. Thanks for the reply bladenbullet. Very unfamiliar with electrical issues in cars. What is the best way to trouble shoot the issue and pinpoint where the problem is?

 

[MO Viet Vet]

Did they both stop working at the same time?

 

[bladenbullet]

its a 2007 chevy Tahoe LS. I have tried the passenger front main switch and it works both ways. Thanks for the reply bladenbullet. Very unfamiliar with electrical issues in cars. What is the best way to trouble shoot the issue and pinpoint where the problem is?

the rear window switches are fed by the master switch....the master switch may operate the windows but not provide the proper feed for the slave switches...

just a possibility....

 

[rockenthebowtie]

Did they both stop working at the same time?

Good point raiderron. I have a good point too but I let my hair grow longer than I would like to cover it

 

[Chevyman07]

both windows stopped working at the same time

 

[rockenthebowtie]

Well I have to say that Ive never seen that happen beforw what you might want to try is with the one of the doors open is grab a hold of the weather protector black rubber boot thats between the door jam and holding the rear door switch in the up position wiggle the boot if the window rows up you may have a shorted or broken wire inside of the insulation if not the only thing I see that it can possibly is the body control module the switches do not power or ground feed the window motors its thru serial data that the signal is sent to the BCM and the BCM powers and grounds the window motors

 

[MO Viet Vet]

If both stopped at same time then that is strange but suspect the master switch like bladen said but also check the harnesses like rocken.

By the way, ElGuapo, I thought you just used a hat to cover the point. You know, like the conehead hats from SNL.

 

[bladenbullet]

you have to take your hat off at the table...hair is the only true 24/7 alternative....

 

[MO Viet Vet]

:facepalm:

:happy175:

 

[rockenthebowtie]

I loom like a walking hat rack if i do that...actually the right rear is fed thru the right front window switch and the left rear thru is fed thru the left front switch the bcm receives a signal via class 2 serial data thru the rear switchs and then will supply power and grounds where the circuitry runs like i mentioned

 

[bladenbullet]

my kingdom for a schematic & circuit description....remember when things were simple?....but back then onstar couldn't unlock doors...

 

[rockenthebowtie]

@bladenbullet we didnt need onstar we had juan-star

 

[bladenbullet]

 

[bladenbullet]

boy....talk about your coincidences....

both my rear windows stopped working with the rear door switches at the same time....the control circuit is different than previous master switch controlled rear windows used to be....the rear switches have their own logic circuits and it appears that if the lockout signal is good and there are power and ground wires doing their job at the switch then the switches themselves would be bad....dont ask me how 2 throw out at the same time but it looks like thats what ive got....

both switches have active signals at the lockout terminal and the power/ground wires are good...the switches receive signals from the bcm to operate with the master switch but use their own logic and internal connections to operate independently...the old setup was way too simple but of course wouldnt lend itself to remote function....

i was jumping back in here to see what the outcome was on this thread before i started spending money but i cant find any other alternative looking at schematics, a scanner and my power/ground checks...

was the problem in this thread resolved and what was the result?....

 

[rockenthebowtie]

Ahhhh, Thats what I was sayin in my post about description and operation lol..

 

[bladenbullet]

:happy160:

and one of the reasons I am looking for the resolution found by the op....although I am not going to hold my breath...

 

[bladenbullet]

ok....wow....who would have thought....

the rear windows are operated 2 different ways on this vehicle (2007 tahoe)...
the master switch communicates with the body control module to operate and/or lock out the rear window switches...the rear window switches have the only power and ground feed for motor operation...the rear window switches have their own logic circuits built in to determine what to do per signal from the bcm or the switch itself...neither rear switch has a relationship with either front switch as most previous power window circuits....

both rear switches were inop regardless of master switch lockout position and the lockout and unlock signals to the switches were functional...this left only one conclusion....both rear window switches failed at nearly the same time (they worked recently prior to this) or i am losing my mind....i found a dealer online with good pricing and bit the bullet for 2 switches trusting my diagnostic abilities and only being out $43 if i was wrong...

installed the switches this morning and both operated as designed...repair successful...

unusual to see 2 switches fail at about the same time but poop happens...

just wanted to relate the repair....