2007 Sunurban buzzing noise thru rear speaker?

Its an electrical interference. Have you ever been near one of those big electrical junctions by the road that constantly buzz or hum. All electricity causes some sort of magnetic field and a magnetic field can cause electricity. Its how starters and alternators work. The electricity in the wires running to the back of the car is causing a magnetic field. The speaker wires are close enough that the magnetic field is creating electricity in the speaker wires which is amplifying into a sound.

Well I t just dtarted after I got it out of the body shop. the onlt thing that was removed was the hood to repair three dents and I think they removed the lift gate for the same reason. So I'm not having to spend a lifetime chasing wires, do you have any suggestions?

If you have the money to throw at it start by replacing the relay its inexpensive anyhow and if that doesn't fix it replace the switch and if that doesn't fix it take it to soneone who knows how to trace electrical problems. Without it being a constant issue it will be even harder to find also. The only shortcut when fixing electrical is replacing the least expensive and most logical part first. Since there are only 2 possible culprits it will be a little bit easier. I truly hope one of those two fix your issue.

Well now it’s doing it all the time. When I accelerate it accelerates it’s just more pronounced when the radio is on and the volume is up just a hair.

For some reason my last answer got put on the wrong post. That answer was for a gentleman's headlights. The only thing you can do is trace the speaker wire it quite possibly got nicked and is now touching the metal. When they had the rear tailgate off something got moved or a wire is lose or bare wire touching bare metal. Only thing you can do is get in the back, pull the panels off and start moving wires until it stops.

There's no speakers in the liftgate. can you suggest where I van find a diagram?

There won't be a diagram showing you where the wires run unless you get lucky and find something done for educational purposes. The speaker wires run through a wire loom that runs throughout the truck. The speaker wires are run through the same loom as the rear lift gate wires. The ones for the wiper, third brake light, any lights on the inside of the gate, etc. They take the vehicles wires and run them all together and as they get near their destination they branch off. Only thing you can do is remove the panels covering the speakers and trace the wires back through the loom and look for signs of tampering. If it was in the body shop for dents then they probably removed those panels to gain access to the inside of the body to tap out the dents.

The litigate was the only thing removed and the body shop is claiming everything (all the wiring) was just a connection of male to female wiring adapters. Basically they claiming they did nothing wrong.

I had this same problem on my 07 suburban, it took 2+ years to figure it out and the noise got worse over time. they fixed my rear audio control in 2011, now the noise has started again---I have called GM insisting on a recall of a bad part--you all need to do this so they recall the part. one person isn't enough

I have the same problem in my Suburban 07. It started after I serviced central console and reconnected the main plug. Definitely it is a problem with rear audio control unit.

I have an 08 suburban that is making the whinning sound. Has anyone figured out exactly what is causing it?

So far no solution to this issue is available. I disconnected the rear audio control unit but the sound is still there. I am working on it...

I tried a new thing. I gave a strong negative directly from the battery to car body. The noise has reduced considerably but definitely still there. Here John has a point...

I have the same problem in a 2005 GMC Envoy. It only in the right rear speaker. Even with the radio shut off the noise is still there.

I had an intermittent buzz (sounded like alternator noise) through my back speakers. If I smacked the center console it quit. Then I found that it could be the rear AC/radio control unit. Before I bought a new one, I removed the control unit and found that it is two circuit boards screwed together with a multi-pin connector. That connector was somewhat loose. So I unplugged it from both circuit boards and then plugged them back in tightly. Reinstalled the unit adn no noise since then. Glad I save $120+!!!

Where is the control unit that you replaced jnssctt?