Hello all! I have a 14 suburban lt and I have the unfortunate whine that's worse upon acceleration, I unplugged the rear climate control unit and confirmed that's the cause of my problem, I also learned it being unplugged stopped my rear speakers from working. I seen tons of post of people just replacing it and at about 150$ I'm not opposed to it I was just wondering if anyone has ever opened one up and found the cause and repaired one ? Bad resistor or something? I'm also interest in a wiring diagram of both plugs for the unit if anyone has one , I'm curious how the rear speakers are tied into it, thank you to anyone who has any ideas or can chime in to help

 

Just wanted to update that I replaced the rear climate control unit and the problem still persists , if I reach back and turn the power off it goes away. Currently searching the forum and Internet for another solution.i have questions if anyone could answer them? Since I haven't had one response it's doubtful but I will definitely appreciate any advice . How can I prevent the rear climate from turning on with the vehicle every time ? As needed basis ? Is it possible a ground loop isolator could redo resolve this ? Is it possible to wire the system back together with this disconnected from the equation ,? Thanks to anyone who can help with this !

 

I can't comment on the source of the whine, as this is a new subject to me, but as far as having to reach into the back seat to turn things off...

Isn't there a control on the dash that lets you manage the rear HVAC from the front, without having to reach back there? Every SUV I've been in that had separate rear AC controls had a way to control it from the dash as well, as often you have little kids back there, and need to manage the heating and cooling for them. That should let you turn it off as well, and it should stay off unless you have it set to be managed from the rear seat.

 

Maybe try running a ground wire the the rear control to the frame??

 

The rear button on the front shuts off the vents back there, and let's me control them it does not shut the control units power off though it still has power regardless for audio too

 

Are the rear controls for both integrated in one face or mounting??

 

See attached, if I push the power button in the middle the whine is gone. It increases with speed , if I unplug the unit I get no rear audio. I've already replaced it with a second hand unit and it's the same situation and noise. It's very possible I received a bad unit being that it was used but I don't want to have to purchase another I wish someone had already worked out how to wire this module out of the loop and just leave it in place

 

So, let me ask... is the whine coming out of the rear speakers, or from the head unit itself? Sound like it is not actually related to the rear HVAC unit itself if I am understanding this right.

Someone else mentioned checking/adding a ground. That could be useful, but first, see if the whine is from the head unit on that center console, or of it is coming from the speakers in the door/rear. Maybe someone needs to drive while you ride back there and listen...

 

Is the whine a constant noise or does it change frequency with engine speed?
Is it present with engine off & key on/system turned on??