This annoying whine

[Dbld54]

Hi, I needed Assistance troubleshooting an annoying whine coming out of my speakers.
I think it started when my ground point in the trunk, became loose and I had to try different areas but not too sure.

I have two amps, I've disconnected the subwoofer amp to try and keep it simple.
This leaves the 4 channel amp.
Clues:
The sound does not get louder when I increase the volume.
It is present even with volume at level 0 on the HU.
If i disconnect the 4 rcas the whine is gone. If I connect any rca cable to any of the Jacks the whine returns. Even if it's just 1 rca, that one speaker will whine.
I've tried several ground points, the latest is using an existing ground from the stock Ford wiring.
The ground points are sanded and tightly connected.
Amp fuses are fine.

Please let me know if you have any ideas.
Thanks

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[audiobaun 5,000+ posts]

Do you have a Pioneer HU/Radio??

 

[Dbld54]

Do you have a Pioneer HU/Radio??

Yes, pioneer Deh-7900bt.

 

[audiobaun 5,000+ posts]

Yes, pioneer Deh-7900bt.

So did you place and remove the RCAs while the amp and HU were in operation??

 

[Dbld54]

So did you place and remove the RCAs while the amp and HU were in operation??

Yes

 

[audiobaun 5,000+ posts]

Yes

It is very, and I mean Very possible that you Blew the Pico Fuse inside the HU by doing what we call Hott RCA swapping. Pioneer had this issue with several units in the past and especially when I had a 99PRS that wasnt so cheap at the time I bought mine. I havent purchased any more Pioneer units since that time, and I can not verify if they have fixed the issue with newer units..

 

[audiobaun 5,000+ posts]

Ive done hott swapping for over 25 years years with RCAs on several HUs without ever having an issue. Only until I bought 2 99PRS units. Sent one in for warranty and bought another until That one came back. the T/A on my second one had issues. I tossed it out, put in an older Eclipse CD3000 hu and never had any issues, and Pioneer Voided my warranty for user error. Thanks Pioneer

 

[Dbld54]

Ive done hott swapping for over 25 years years with RCAs on several HUs without ever having an issue. Only until I bought 2 99PRS units. Sent one in for warranty and bought another until That one came back. the T/A on my second one had issues. I tossed it out, put in an older Eclipse CD3000 hu and never had any issues, and Pioneer Voided my warranty for user error. Thanks Pioneer

Thank you for the valuable experience. Before I open up the HU, and probably start a new thread for that, is there anything else you can think it might be? Any tests I can do and share results for better Process of elimination?

 

[audiobaun 5,000+ posts]

You can try and place some wrapped 14 ga speaker wire around the RCAs at the back of the HU, that will look like a Rats nest and ground those out to a bolt under the dash/Solid Bolt, and get some better results. You can do a You Tube Vid search on it. Other than that.. Id try to get a warranty return on it as a defective unit, and get another brand in replacement such as Kenwood/JVC, or Alpine

 

[audiobaun 5,000+ posts]

Thank you for the valuable experience. Before I open up the HU, and probably start a new thread for that, is there anything else you can think it might be? Any tests I can do and share results for better Process of elimination?

If the unit is under warranty, Get a Return # and send it in. If not.. Id try Pulling it from the vehicle and set up a small testing station with a battery and an amplifier and a set of speakers. A charged 420cca lawnmower battery works just fine or use the car battery. If it does it while testing.. you will know for sure. If its under warranty.. Send it back as a defective unit and swapp for store credit for a different brand HU as stated.

 

[Dbld54]

If the unit is under warranty, Get a Return # and send it in. If not.. Id try Pulling it from the vehicle and set up a small testing station with a battery and an amplifier and a set of speakers. A charged 420cca lawnmower battery works just fine or use the car battery. If it does it while testing.. you will know for sure. If its under warranty.. Send it back as a defective unit and swapp for store credit for a different brand HU as stated.

Thank you, definitely out of warranty.
I have a new clue and I think it confirms its the pico fuse like you mentioned. When the car is running, if I give it gas in park, revving the engine, the loudness of the whine increases, and then decreases as I let off the gas.
Do you think this is confirmation?

 

[audiobaun 5,000+ posts]

Thank you, definitely out of warranty.
I have a new clue and I think it confirms its the pico fuse like you mentioned. When the car is running, if I give it gas in park, revving the engine, the loudness of the whine increases, and then decreases as I let off the gas.
Do you think this is confirmation?

That is not a 100% guarantee of the culprit, as a poor ground location of the HU as well as the amplifier could be the issue. Buuut.... With the Hu out and testing on the bench or work table and it persist it would be the culprit for sure. You could try another ground wire from the amp as it sits to say like your rear end frame bolt with the car off to see if it persist. If it does not its possible the ground may be the issue. Start vehicle up with the other added ground and if it still does it.. then yes I would say its the issue. I tried these methods as well as new RCAs and 3 different amplifiers. Ive seen Vids of people Soldering a solid wire where the Pico Fuse blew and they ended with great results, and some damaged the board. Got be good with soldering. Id research it if youd want to try it out yourself

 

[Jimi77 5,000+ posts]

Thank you, definitely out of warranty.
I have a new clue and I think it confirms its the pico fuse like you mentioned. When the car is running, if I give it gas in park, revving the engine, the loudness of the whine increases, and then decreases as I let off the gas.
Do you think this is confirmation?

That's a ground loop. This trick will fix the issue if it's the pico fuse. I also run a ground from my amp ground to the HU ground (~14awg) to avoid ground loops.

Pioneer pico fuse work around - quick question

www.diymobileaudio.com

 

[audiobaun 5,000+ posts]

That's a ground loop. This trick will fix the issue if it's the pico fuse. I also run a ground from my amp ground to the HU ground (~14awg) to avoid ground loops.

Pioneer pico fuse work around - quick question

www.diymobileaudio.com

I clicked on that Link man.. And it didnt do anything for me.. went straight to this Forum ??????? Im sure he can still research for himself

 

[Jimi77 5,000+ posts]

I clicked on that Link man.. And it didnt do anything for me.. went straight to this Forum ??????? Im sure he can still research for himself

Did the same for me??? Maybe we aren't supposed to direct people to a competing forum? I'll try this: