[rewdpost]

I've had my 04 SL MO for about 8 months now and just recently I started to see (hear) a problem with it.
Being in Portland, we get a lot of rain and it tends to be pretty cool out at this time of year.

Now this isn't all the time, but at least 4 times in the past month or so I've been getting what I can only describe as a hum coming from somewhere in the electric system in my MO. It only happens when it rains and will go away after a night in my garage drying out. I can turn off the stereo and the fans, but still hear the humming/buzzing.

I'm thinking there might be a leaky seal somewhere on the MO, but wanted to check to see if anyone else has experienced something like this before I take it in to the dealer.

My big concern here is that this doesn't happen every time it rains, so reproducing the problem for the dealer may prove difficult.

Any suggestions out there?

 

[jaak]

Hmmm.... I'll be there in June. If it's still doing it, I'll have a look!

Just kidding, I'll be there, but I'm sure I'll be busy with new product training. (Tek)

I've not heard anyone report this before.

And it might be tough to diagnose, when it's not doing it.

Does it sound like it's coming from one, or more of the speakers? If so, it might be interesting to wiggle the connectors on the PA Amp (behind the right rear passenger seat, fold it down, lift the flap and reach in.) to see if that affects it at all.

Have to localise it first, to determine what to do next.

 

[rewdpost]

Localizing the sound is tricky on this one.

I swore that it was/is coming from the speakers mounted on the dash, but when I lean in to check for the sound, it's clearly not up there.
I've literally crawled through my car trying to find the source of the buzz, but all I can tell is that it might be coming from somewhere in the rear of the trunk.

I thought speakers right away too, but (and maybe this is naive) shouldn't turning off the power on the stereo cut out the buzz then?

I don't know, I'm going to have to localize it before I take it in for a look. I have noticed that the seals on the MO aren't so great when I got it back from the car wash (pressure only, no brushes) and had soapy foam near in the inner portion near the trunk hinge.

 

[Tyler_Canada]

In The Murano (with Bose), the amp is on any time the key is set to Accessry or On. So it is conceivable that it is the amp/speakers.

 

[jaak]

Well, to determine if it's the amp, when it happens, leave the ignition on and go back and unplug the connector to it. You won't harm the amp doing this, and you'll quickly find out if that's the problem.

Turn off the ignition and plug it in, after you've seen the results.

 

[MOpar]

I think the amp is on only when the head unit is on.

 

[jaak]

The amp has unswitched power direct from the Battery. So if there's a fault in it, the radio doesn't have to signal it to turn on.

So part of it, is always powered.

 

[rewdpost]

The amp has unswitched power direct from the Battery. So if there's a fault in it, the radio doesn't have to signal it to turn on.

So part of it, is always powered.

Good info to know jaak.
I'll check into it when I get the buzzing again next time. I had it for just a second last night (rain here, again...) but it stopped pretty quickly. The only interesting thing that I did notice was that while most of the speakers are silent with the radio/head unit turned off, I'm still getting some white noise from the 2 speakers in the rear doors. Now I'm sure I'm over-sensitive to this stuff now that I'm having problems, but I'm wondering if this is normal, or not.

Hopefully I'll get the buzzing again soon and can identify the location of the noise and then drop by the shop to get someone to confirm the noise before scheduling a time to fix it.

 

[Tyler_Canada]

I was able to hear a slight hiss from my speakers all the time with the radio off, but the key turned to Accessory. It had to be really quiet in the car to be heard, but it was typical amp noise.

 

[jaak]

I've never noticed it, but I'll take a listen next time I get a chance. With all the time I spent in the back with a Logic Analyser on the Sat receiver, I would have thought for sure, I'd notice that!

 

[hfelknor]

Often the "hiss" Is a fairly high frequency and older men who have lost their mojo cannot hear frequencies that high.

Homer

 

[jaak]

Oh great, you would remind me.... Long gone are the days when I could hear up to 20.5 KHz... Last I checked I'm down to around 17. Probably less now.

Last half a year I've found I need reading glasses for some of the chips I look at... Getting old sucks, but the alternative sucks more.

 

[rewdpost]

Fortunately the hissing isn't the problem that I'm having here, good to know that this may/could be normal for those speakers though.

The hum itself it quite audible and not a high frequency really. Like I said before, when it comes back I'll pull off somewhere and start to figure out where the sound is coming from. Hopefully that will help things out.

 

[zebelkhan]

Often the "hiss" Is a fairly high frequency and older men who have lost their mojo cannot hear frequencies that high.

Homer

Good to know that the hissing that I hear in my bad ear is the frequency that I should not be hearing but I am "hearing...:2:

 

[rewdpost]

So I'm more or less replying to myself here, but I've actually found A cause (might not be THE cause) of the hum, or at least a way to reproduce the situation.

So, here's what I found, tell me if this sounds weird to anyone else:

Nissan has that nifty cell phone holder in the center console, right? Well it turns out that when I have my cell phone in this holder and am making a call (using a headset of course) there seems to be some sort of interferance caused by the power the phone is putting out.

I guess the question now is two-fold, first, is it the cell phone itself causing the problem (ie is there something wrong with the cell phone) and secondly, even if it is the cell phone, since Nissan clearly intended a cell phone to be stored here, shouldn't any electronics in the console be shielded from interferance, or at least not be noticable affected?

I don't know if the first step is to try to replace my phone and see if that makes a difference (it was recently dropped and this may have done something to it) or if I should take the MO in and reproduce this problem for the dealer and see if they have a suggestion. Well, one other than don't use the cell phone in the holder.

 

[jaak]

You have a GSM or TDMA cell phone then, or even an iDen phone. It's highly unlikey a CDMA phone would be doing it.

This is not because one is better than the other, but is a reflection of the radio emission and your Murano's ability to be immune from this.

Move the phone around and see if it get's significantly worse anywhere and this will help confirm it.

The fix may be a loose ground, or it may be a sheilding problem.

There is no fault with the phone. Also, I suspect Nissan designed that as holder for the phone, not really expecting it to be used while in there.

Most dealers are clueless with this stuff.

What phone model/make is it?

 

[rewdpost]

At least it seems like we're finally getting somewhere with the problem.

The humming seems to be directly related to the space that the holder occupies, or at least something around there because literally when I move the phone in and out of the space the hum comes and goes. I can't say that I've really played around with it in any other areas yet, but I know that I can still have the phone on in the car (ether on my lap or on the seat next to me) and not get the interferance.

For what it's worth, the phone is a Nokia 3560 which seems to imply that it's a TDMA phone. I believe that there are actually plans for us to move to new phones that support GSM soon (thanks to the merger between AT&T and Cingular) but I don't know if/when that will be happening.

Jaak, do you have any suggestions on where to start looking for grounding issues? This all just seems so odd to me.

 

[Tyler_Canada]

I thought it might be the cell phone. My cell (GSM) is particularily audible on any type of amplified speaker system within 20 feet. Every once in a while it makes a sound, but if I'm sending/receiving text or talking, it's a constant loud hum. I can hear it on my home stereo, my computer speakers, and when it was stock, my Murano sound system.

You may still hear this with the radio off, if the amp is actually powered whenever the key is at Acc or On.

 

[jaak]

It's all fixable... I used to do stuff like that for a living.

I'll get back later as I have to go.