Stock head unit problems

[srrueve]

Head unit is stock Sony sync 3 Fiesta St
Speakers are 6.5” focal (haven’t put in tweeters yet)
Amp is a Memphis audio street reference 150x2

So I finished installing my amp and everything and i now have a high pitched whine coming from my speakers.

I don’t believe it’s a ground loop, I had alternator whine as well with that whine but the alternator whine went away after finding a better ground, but the constant whine stayed.

I have to keep the head unit stock because it’s too integrated into my car so I can’t try a different head unit. I tried grounding the head unit to the amps new ground and no change.

I also have to use the stock speaker wiring as there is plugs from both sides of the cab containing all of the wires for the doors.

I am using a high input that plugs into the amp. Tried a line out converter and same thing was happening. Happens with both a loc and the high input on the amp. Did not go away with ground isolator either.

What I am asking now is would it be the head unit causing the noise, or would it be something else? Any potential solutions I would like to hear as well

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[huberoy123 10+ year member]

Have you tried eliminating the amplifier from the equation (disconnect it). See if the whine disappears. If it doesn't, look at the head unit and associated power/ground. If it goes away, look at the amp and associated power/ground wiring. Good luck in your troubleshooting.

 

[srrueve]

Have you tried eliminating the amplifier from the equation (disconnect it). See if the whine disappears. If it doesn't, look at the head unit and associated power/ground. If it goes away, look at the amp and associated power/ground wiring. Good luck in your troubleshooting.

No whine if it is disconnected however there was no whine until I added the amp. There is no factory amplifier either the head unit is the only signal source. With head unit disconnected, no whine. Whine starts only when head unit is on which I probably should have stated before

 

[HardofWhoring]

If you are able to, leave the head unit connected, but pull it out so the wiring is as free as possible. A pinched wire, a cable end that has pressure or force on it can cause whine. See if there is whine, give the wiring a little jiggle if you can just to make sure. Follow the wires for the short distance behind and see if there are any pinched or with broken strands.

Why is your head unit not using it's original factory ground (probably through the harness)? Did you change this after getting the whine to try to get rid of it? Did you try it again after getting rid of the alt whine?

Those plugs probably come out, and sound like they are basically grommets so the metal won't contact the wire.

If you can reach the wiring you can also try disconnect em in pairs and just verify it's not the speaker wire, (possibly cut). Can you verify it's all the speakers causing the whine or just one or two?

 

[srrueve]

If you are able to, leave the head unit connected, but pull it out so the wiring is as free as possible. A pinched wire, a cable end that has pressure or force on it can cause whine. See if there is whine, give the wiring a little jiggle if you can just to make sure. Follow the wires for the short distance behind and see if there are any pinched or with broken strands.

Why is your head unit not using it's original factory ground (probably through the harness)? Did you change this after getting the whine to try to get rid of it? Did you try it again after getting rid of the alt whine?

Those plugs probably come out, and sound like they are basically grommets so the metal won't contact the wire.

If you can reach the wiring you can also try disconnect em in pairs and just verify it's not the speaker wire, (possibly cut). Can you verify it's all the speakers causing the whine or just one or two?

I will try this later tonight and let you know how it goes
The whine comes from all speakers and I went back to factory ground since it didn’t help, also yes tried after getting the whine after resolving the alt whine since I figured it was still a ground loop

 

[srrueve]

I will try this later tonight and let you know how it goes
The whine comes from all speakers and I went back to factory ground since it didn’t help, also yes tried after getting the whine after resolving the alt whine since I figured it was still a ground loop

If you are able to, leave the head unit connected, but pull it out so the wiring is as free as possible. A pinched wire, a cable end that has pressure or force on it can cause whine. See if there is whine, give the wiring a little jiggle if you can just to make sure. Follow the wires for the short distance behind and see if there are any pinched or with broken strands.

Why is your head unit not using it's original factory ground (probably through the harness)? Did you change this after getting the whine to try to get rid of it? Did you try it again after getting rid of the alt whine?

Those plugs probably come out, and sound like they are basically grommets so the metal won't contact the wire.

If you can reach the wiring you can also try disconnect em in pairs and just verify it's not the speaker wire, (possibly cut). Can you verify it's all the speakers causing the whine or just one or two?

Tried taking head unit out earlier and checking wires and still no luck
Would the wiring harness on the stock unit be causing feedback to the amp?

 

[1aespinoza 10+ year member]

taking head unit out earlier and checking wires and still no luck
Would the wiring harness on the stock unit be causing feedback to the amp?

On my nephew's truck I installed a Digital Designs SC2 LOC. It got rid of the whine that developed out of nowhere. It is the OEM Dodge radio with UConnect.

 

[HardofWhoring]

Wait, so the whine only happens when the amp is connected, and only from the speakers that are connected to the amp? - If this is true, it has to be your amp's ground. Even if it's a small amp, the grounding path is still the same, (the path of least resistance, and ending at chassis).

If it's anything else, can you connect speakers directly to the head unit, and speakers to the amp, and see if they all whine? If it's only the amp speakers then it's your amp's ground.

If it's the head unit speakers too, then it's one of your other grounds.

Your amp should be grounded to bare metal, have to clean it to bare metal if it's paint or coating,

 

[srrueve]

Wait, so the whine only happens when the amp is connected, and only from the speakers that are connected to the amp? - If this is true, it has to be your amp's ground. Even if it's a small amp, the grounding path is still the same, (the path of least resistance, and ending at chassis).

If it's anything else, can you connect speakers directly to the head unit, and speakers to the amp, and see if they all whine? If it's only the amp speakers then it's your amp's ground.

If it's the head unit speakers too, then it's one of your other grounds.

Your amp should be grounded to bare metal, have to clean it to bare metal if it's paint or coating,

Okay, so basically it’s still a ground loop? But then why would the alt whine go away but the other constant whine stay
Sorry I’m just pretty new to all of this and I want to understand better.
If it helps I have a sub grounded in the same place and no sound from that