Help with Buzzing Noise

[JCPDS3]

Hey All,

I posted this question in the New Owner's forum but only got one response so I'm reposting here in the hopes getting a couple other options before I break down and take the NSX to have it looked at. Here's a description of the problem I'm having:

My NSX has a buzzing sound I'm having problems troubleshooting and I hope you can give me some assistance. The buzzing sound seems to come from the door speakers, and I've noticed my stereo makes a "thump" noise when I turn the car on. The pitch of the buzzing changes by the RPM of the car, starting off low and raising in pitch as the engine revs higher. I've tried a couple things detailed below and hope you can give me some advice as to what to try next:

1) I tested to see if it were the aspirator fan even though the sound seems to come from the speakers. The sound only occurs when the engine is actually on, not when the key is set to the "ignition" setting so I don't believe it's this. I also tested the method in the wiki, which suggests starting the car, turning it off, then switching the key to "ignition" and the sound did not come back.
2) I removed the fuses for the speaker amp and the radio/center console, and the noise still occurs even after I've verified the radio is not getting any power and cannot turn on.

As a side note, my antenna also does not go up when the radio is turned on.

Thanks in advance for any assistance you can provide.

Jon​

 

[SFNMNSX]

Could be a bad ground somewhere. Either A- bad location, B- bad connection, or C -Bad equipment. In that order. If you have the know how to trace it, give it a shot.
My tuner solved this problem for me since I have NO electronics knowledge. It seemed fairly easy as I did not get charged a lot for the fix.
Also, check your alternator, alternator whine.??? HTH.
=DREW=

 

[JCPDS3]

Thanks for your insight! Is there a quick way to test the alternator (ex. disconnect something)? Or will I need to hook up a replacement to test?

 

[chrisbailey13]

Do you have a factory stereo, or aftermarket?
If it is aftermarket, I would first try to disconnect the ground wire from the head unit. if there is an aftermarket amp, check to be sure there is no paint underneath the amp ground wire connection.

 

[SFNMNSX]

Chrisbaily13 is right, check your stereo system ground wires first. If it's grounded to the frame, make sure there is metal/metal contact, and make sure it is tight. After reading a bit about this on other car forums and question/answer sites, it seems that the alternator whine sound through speakers is caused by a bad ground. I typed in google: "how to fix alternator whine in speakers".

My volts were dropping below 12 when I installed my SC, but I did not get a whine. My lights would dim at stops and the car nearly died each stop. A smaller pulley solved that problem. OK, off track...

I did have a buzzing sound through the speakers when I had my gauges installed....BAD GROUND. Sheesh!!! Electronics is crazy.
You could look at your volt gauge and make sure it's not dropping below 13. Autoparts stores can test your alternator for free,but after reading more, I don't believe that is the problem. Good luck, let us know.

=DREW=

 

[JCPDS3]

Thanks for the replies, everyone! As soon as I get some free time off from work, I'll look into your suggestions and report back.

Jon

 

[Old Guy]

I am going to presume that you have the stock factory stereo system.

Just to confirm - when you pulled the fuses to the stereo system, did you pull fuse #51 in the main relay box? This is the fuse that provides power to the power amplifier relay. If this fuse is removed, the door and subwoofer amplifiers cannot receive DC power (unless a previous owner got in there and made some modifications). If you are still getting noise from the speakers with this fuse pulled, then your noise is probably not electrical in nature. I would suggest you start looking for loose stuff in the doors!

Normally, since the buzz you describe is tied to the engine speed, an obvious candidate to check would be the noise supression capacitor (repair manual refers to it as a noise condenser) in the igintion system. I have attached a .pdf showing the location in '97 and later cars. However, the stereo system would have to be on for you to get this ignition related noise and that does not seem to be your case.

 

[SFNMNSX]

Hello all,

I have a new electrical bother. It is a buzzing/humming sound from what seems like under the engine bay fuse box. I notice it when I park in the garage and shut off the vehicle. It's not a continuous hum, but an irregular intermittent hum, and not very loud. Hmmm... I even pulled the battery cables completely off and it continued!!! It will start/stop sounding with me smacking the fuse box cover with my hand...
I'm not noticing anything wrong with any electronics, just the sound.

If this sounds familiar, let me know if I should be concerned and if there's a fix.. Thanks,

-DREW-

 

[Valhalla]

Fuel system losing pressure?

 

[SFNMNSX]

I don't Know... How do I check? I do have difficult starts.

-DREW-

OK. I see how to check pressure looking in the service manual. I may be able to check tomorrow.
The manual reads that the pressure should be 46-53 psi. Is this measure different for my NSX being supercharged?
And so, what is the humming sound?

-DREW-

OK. My SoS SC installation Guide reads that my pressure should be 49psi +-5.

Again, what's humming?

-DREW-