What is this noise?

[Tdub4]

I recently changed out the stock radio from my 2007 GMC Yukon and added an Advent navigational unit. This unit is as close to factory as possible with a very easy plug and play interface while keeping nearly all of the factory options in tact (OnStar, steering wheel controls,etc.).

The issue I am having is that when starting the car it will randomly make a loud noise before the radio comes on. This isnt a consistent occurence...sometimes it will happen between back to back starts and then sometimes it can go a day or two - and it only happens when starting the car.

I have had a a couple of people look at it and have not been able to figure it out yet - wires look good, grounding seems good, etc, but thought I would post to see if anyone can identify this as a noise they have heard in one of their installs before. I do have some alternator whine but not too bad and can not be heard when listening to the radio at comfortable listening volume. See video below, it happens just before the "GMC" splash screen appears. Thanks in advance!

(Because I am new, I cannot post the video, so here is the link and hoping you will click it to be directed to the video):

http://www.youtu.be/SlBF0tEv_QY

Click to read more...

 

[All_Logix 10+ year member]

Does your Yukon have the BOSE system, and if it does not, was that HU originally manufactured for the BOSE system. sorry to say I am not very familiar with their nav screens

 

[jirehn 10+ year member]

Well that is really bad, This is my first time to hear that such problem.

 

[Tdub4]

Does your Yukon have the BOSE system, and if it does not, was that HU originally manufactured for the BOSE system. sorry to say I am not very familiar with their nav screens

It does have an option for turning the factory amp on or off. Per the directions if the car has Bose, which mine does, then this setting should be set to on. I did set it to off yesterday to see if that changed anything but still got the noise. Just trying to determine if this is a wiring issue or HU problem.

 

[Tdub4]

Well that is really bad, This is my first time to hear that such problem.

Thanks for the reply...I haven't found anyone that has heard this before and hoping someone may have and say what they found.

 

[All_Logix 10+ year member]

very strange... Does the sound come from every speaker in the vehicle... try setting your fade and balance to isolate individual speakers and see if it continues to play from every speaker. If the sound comes only out of the speakers that have been isolated with the Fad/Bal on the HU, more than likely the problem exist in the HU or in the connect to the BOSE amp. If the sound continues to come from all speakers, the problem is originating in the BOSE amp....I assume

 

[Tdub4]

I haven't been able to work on this in the last week, but is it possible this is a type of amp pop? In other words the amp needing to be delayed a bit before the HU boots up and cycles on?

 

[mylows10 5,000+ posts]

prolly the deck then,if you didn't have the noise before replacing the hu, but you do now.

 

[ThatChevyGuy 5,000+ posts]

That would scare the **** out of me in the morning

 

[maylar 10+ year member]

If you wait till the car starts and is running before turning on the HU does it still make noise?

 

[Tdub4]

If you wait till the car starts and is running before turning on the HU does it still make noise?

This would seem like an obvious thing to test but I hadn't done it until this morning. Anyway, the times I did it this morning, the answer is no it does not make that noise. The sound is not consistent -sometimes it does it and sometimes it doesn't - so it is possible the sample size of the test this morning wasn't enough but so far , it hasn't made it. That being said, what is your thought if it doesn't happen when the radio is off at the time of the car starting?