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View Full Version : 08 22SSV Stereo Engine Noise Issue



klewis
07-02-2014, 11:46 AM
I've read posts over the years about the stereo developing engine noise over time. Now mine is doing it.

I get high pitched whining at idle, louder with RPMs. It also does it with any accy on like the blower or the air pump plugged into the cigarette lighter adapter.

I have:
Head Unit: Kenwood KTS-MP400MR
AMP: Kicker ZX200.4

Stock system, one amp, no sub, no tower speakers. The audio system isn't anything more than the basic stock system.

I have read posts here before and more about engine noise over on wakeworld and it seems the common issue is the grounding going bad over time or being done incorrectly from the factory.

I am the original owner of this boat and it did not start having this issue until the past couple of seasons, it's now so bad the stereo is unusable.

I'm not an audio guy, but I also hate paying to have things fixed and my wife is ready for me to take it to an audio place to pay. I'm hoping someone here can help me out before I admit defeat.....

Grounds: I checked all of these and they are solid and clean. The head unit is grounded to the amp and the amp is grounded to the second battery negative terminal. I read that I should try to run a ground from the HU straight to the batter to see if that works, but I didnt want to cut and redo the ground wire yet if it was something else.

AMP Gain: It was factory set at about the noon to 1 o'clock position on the dial. I turned it all the way down to zero and still had the issue.

Antenna: Disconnected antenna, still makes noise

RCA's from HU to AMP: I unplugged the RCAs from the HU to the AMP and the noise went away. Of course so did the actual music, but when I turned on the blower with the engine off it made no noise and normally in that scenario it would make noise.

So have I diagnosed this properly? Is it the RCA cable from the HU to the AMP that is my issue? I've read that a there is a RCA filter of some sort I can buy? Should I try cutting and rewiring the HU ground wire straight to the battery and not to the AMP?

Thanks!

Wylietunes
07-02-2014, 07:13 PM
RCA's from HU to AMP: I unplugged the RCAs from the HU to the AMP and the noise went away. Of course so did the actual music, but when I turned on the blower with the engine off it made no noise and normally in that scenario it would make noise.

You have determined that the source of the noise is pre amp. This could be a bad cable, so lay in a new one from the head unit to the amp. I would also use a 3.5MM x RCA direct to the amp with an MP3 type music source.

Does the noise caused by accessories, also present with the engine off, or is all noise just present with engine on?

One battery or 2 bank system?

cjtpilot
07-02-2014, 08:45 PM
You have a bad ground for the stereo. Find the ground and clean any surface corrosion off.


Sent from my iPhone using Tapatalk

klewis
07-03-2014, 10:49 AM
Does the noise caused by accessories, also present with the engine off, or is all noise just present with engine on?

One battery or 2 bank system?

Yes noise is also present when engine is off and an accy is turned on.

2 battery system

klewis
07-03-2014, 10:52 AM
You have a bad ground for the stereo. Find the ground and clean any surface corrosion off.

I followed the ground from the wire harness on the HU, it then connects to a larger gauge wire off the pigtail of the harness and goes from there to the amp. Then the amp is grounded to my second battery and no corrosion there.

cjtpilot
07-03-2014, 11:01 AM
I followed the ground from the wire harness on the HU, it then connects to a larger gauge wire off the pigtail of the harness and goes from there to the amp. Then the amp is grounded to my second battery and no corrosion there.
Is the ground wire one piece from head unit to amp? also check any other ground connections like RCA cables for amp etc. I have only ever found one issue when it comes to what you describe. Its a bad ground connection at some point even if it is a slight one.

klewis
07-03-2014, 01:29 PM
Is the ground wire one piece from head unit to amp?

No it is not one piece from the head unit to the amp. This was a concern of mine. The ground for the head unit comes off the same wire harness that has all the audio outputs to the speakers, etc. And the ground wire coming off that pigtail is then connected to a larger gauge wire with a butt splice connector. Then that larger gauge wire continues on to the amp. Now that I think about it I did see what looked like corrosion dust sitting on the ground wire right near that butt spice connector, but I didnt think of it at the time because the connector itself looked clean. Could part of my issue be that the ground from the head unit is running through two different gauge wires with a weak point at the connector? All I can think to do with that is cut out the original butt splice connector and replace it with a new one and cover it with some heat shrink.




also check any other ground connections like RCA cables for amp etc

What do you mean by this? How are RCA cables grounded?

Maybe I should take some pictures tonight of what my wiring looks like and post them to the thread.

Thank you for your help!

cjtpilot
07-03-2014, 01:37 PM
No it is not one piece from the head unit to the amp. This was a concern of mine. The ground for the head unit comes off the same wire harness that has all the audio outputs to the speakers, etc. And the ground wire coming off that pigtail is then connected to a larger gauge wire with a butt splice connector. Then that larger gauge wire continues on to the amp. Now that I think about it I did see what looked like corrosion dust sitting on the ground wire right near that butt spice connector, but I didnt think of it at the time because the connector itself looked clean. Could part of my issue be that the ground from the head unit is running through two different gauge wires with a weak point at the connector? All I can think to do with that is cut out the original butt splice connector and replace it with a new one and cover it with some heat shrink.





What do you mean by this? How are RCA cables grounded?

Maybe I should take some pictures tonight of what my wiring looks like and post them to the thread.

Thank you for your help!

Your RCA cable is a black or white and red connection. Red is your positive and black is your ground in that type of cable. However yes I would go for the butt splice first, if you resplice it use some DC4 (dielectric) grease and pack the splice full or even RTV will work. That will keep water out.

klewis
07-03-2014, 01:47 PM
Your RCA cable is a black or white and red connection. Red is your positive and black is your ground in that type of cable.

Oh gotcha, that makes sense now


However yes I would go for the butt splice first, if you resplice it use some DC4 (dielectric) grease and pack the splice full or even RTV will work. That will keep water out.

I'll give that a try and report back, thanks!

cjtpilot
07-03-2014, 01:49 PM
also while you are going through it clean all connections/plugs with contact cleaner you can get at any parts store.

wotan2525
07-03-2014, 05:13 PM
It could also be that there is another point with a bad ground that feeding into your system. If the cigarette lighter or lights have a bad ground, you could have the same problem.

klewis
07-03-2014, 05:36 PM
It could also be that there is another point with a bad ground that feeding into your system. If the cigarette lighter or lights have a bad ground, you could have the same problem.

Oh man seriously! I hope I eliminate it on the first try, chasing it through the other accessories sounds like zero fun...

Wylietunes
07-03-2014, 06:46 PM
An RCA cable, such as a stereo RCA, is comprised of a left and right channel. each plug is positive and negative. These carry an A/C audio signal, so that outer RCA negative, should not be a direct chassis or 12V DC ground. In most cases we come across, it is just that, DC on the signal negative, that is the source of the noise. 9 of 10 cases, its a result of the audio gear drawing from different battery sources.