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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[Evilelder187]

Well here some valuable information. You have a pico-fuse on the rca output. You'll need to replace. But it goes bad all the time when swapping rca's. Especially it the units live

 

[Jimi77 5,000+ posts]

Well here some valuable information. You have a pico-fuse on the rca output. You'll need to replace. But it goes bad all the time when swapping rca's. Especially it the units live

It's not worthwhile to fix the pico fuse. The work around I posted is the best way to deal with a blown pico fuse.

 

[audiobaun 5,000+ posts]

Well here some valuable information. You have a pico-fuse on the rca output. You'll need to replace. But it goes bad all the time when swapping rca's. Especially it the units live

As Jimi77 has stated and to add as well.. If you you do not take the HU apart correctly you can damage it, and it will then be a parts piece, If you do not use the correct solid wiring, and correct Solder, and Hopefully you do not urn and damage the board as most end up doing by lack of Soldering experience, Its a safe way to do as Jimi77 has recommended, or better yet.. Purchase another unit and start fresh

 

[Dbld54]

Thank you all for taking the time to reply. I've been tearing down the system/wiring trying to isolate the problem. Please take a moment to look at my attachments and recent findings:


1. distribution block lost it's ability to show the voltage, perhaps some clue or maybe irrelevant. Fuses are not broken and it is grounded. Amp powers on fine.
2. deck has rca wire to wire connection, not rca wires to rca jacks on deck, (didn't try the pico workaround)
3. videos show popping sound when going from volume level 0 to 1 and 1 to 0, also and when changing radio stations (in accessory mode) Also when turning on / off the car
4. no popping sounds when increasing volume or leaving radio playing (in accessory mode)
5. I tried using each set of RCA cables on the rear speakers alone, then the front speakers alone. The popping continued in each scenario. (accessory mode)
6. I removed each speaker wire from the amp, one by one, the popping continued.
7. With the car started, the whine is constant, with the car in accessory mode, the whine is not present.
8. When using the power windows, the whine is presented loudest. When accelerating, the whine increases.

Can anyone make sense of this or help guide me to next steps to troubleshoot further

 

[Jimi77 5,000+ posts]

Have you tried a noise filter on the HU? I wouldn't worry about pop going from 0-1, just keep your volume at or above 1.

 

[Dbld54]

Have you tried a noise filter on the HU? I wouldn't worry about pop going from 0-1, just keep your volume at or above 1.

no i don't have any with me. If i purchase, would i need 3? Front/Rear/Sub RCAs

 

[Jimi77 5,000+ posts]

no i don't have any with me. If i purchase, would i need 3? Front/Rear/Sub RCAs

No, a noise filter on the HU's main power input. Something like this:

INSTALL-BAY IBNF40 40 AMP Noise Filter

40 AMP Noise Filter WIRE-AND-CABLE - NOISE FILTER - - INSTALL-BAY IBNF40 Discount Price

www.installer.com

 

[Dbld54]

I tried my subwoofer amp, connected the existing power, ground and remote wires to the amp. I connected new speaker wire from the sub amp to one pair of the speaker wires connected to the 4 channel amp.
With the car in accessory mode - there is no whine and only a very slight pop sound when changing stations.
With the car running - there is no whine at all. Even power windows and accelerating don't produce the whine. The minor pop is still there but quiet. I had the gain at 25% on the sub amp.

I believe the amp is at fault. Any ideas what in the amp i could attempt repairing? RCA jacks/capacitors/?

 

[Dbld54]

.

 

[1aespinoza 10+ year member]

.

You did not get that bad of a noise on the sub stage because it plays 80Hz and below. Since you already tried connecting RCAs individually and still got noise, I will say it is not the pico fuse. When my pico fuse blew, I could use the front RCA channels with no issue. When I connected the rear channels, all whines appeared.
What car is it? I think maybe RF Noise filter may be bad in the alternator if it has one.

 

[Jimi77 5,000+ posts]

Ground the RCA jackets (aka pico fuse work around). Tie the HU ground to the amplifier ground.

 

[Dbld54]

Ground the RCA jackets (aka pico fuse work around). Tie the HU ground to the amplifier ground.

The issue is no long present when using another amp. I don't believe this is related to the pico fuse or HU but i'm just a newb here so i still appreciate your feedback

 

[Jimi77 5,000+ posts]

The issue is no long present when using another amp. I don't believe this is related to the pico fuse or HU but i'm just a newb here so i still appreciate your feedback

You won't get whine on sub amp because it's frequency response is limited.

 

[Jimi77 5,000+ posts]

The issue is no long present when using another amp. I don't believe this is related to the pico fuse or HU but i'm just a newb here so i still appreciate your feedback

The fixes I recommended are close to free. Swapping amps costs money