noise in my car and can’t diagnose

Ok I've been reading the ground stickys and I think that MIGHT be my problem here but I don't know where at.

I've tried everything I can think of from the articles. Basically

-There is a whine noise that varies with alternator when car is on. When car is on ACC the whine is still there though.
noise is also present when I hit the brake pedal.

-There is no noise with speakers hooked up straight to HU, only when the speakers are hooked up through the amp.

-I got rid of the factory ground and power wires and hooked them up straight to battery/chassis (for HU)

-The RCAs are on the drivers side of the car and the power wire is on the passenger side. These are OFC Stinger shielded wires.

- I even switched my HU to my old one that never had this problem and it still had the noise.

The only thing I haven't tried is grounding the RCA cables or whatever because I'm still not sure how to do it. which is correct, ground them to HU chassis or car chassis? I've heard both sides. and mainly do I cut the actual end of the RCA cable where the plastic covers the RCA tip or do i just strip some wire towards the HU end of the cable and wrap wire around it?

Should I even worry about the RCAs or is it a ground problem. I've checked all grounds with no result.

Thanks to all

Is the whine heard at the same time as the fuel pump relay?

Did you try disconnecting the antenna?

Are the underhood grounds in prime condition? At battery, alternator, firewall, engine, etc?

Did you try disconnecting RCA's at amp? Result?

Did you try running RCA's outside the car? (for test purposes only - obviously)

Sometimes a ground loop isolator on the RCA's work.

When you hit the brakes I understand that you don't mean that it whines but that there is a pop, is that so? If so, add a cap to the brakeswitch wire.

thanks for the reply

"Is the whine heard at the same time as the fuel pump relay?"
Umm, it's constant, so no matter how long I leave the car on (ACC or with the engine on) it always whines

"When you hit the brakes I understand that you don't mean that it whines but that there is a pop, is that so?"
Yeah

"Did you try disconnecting the antenna?"
The antenna was initially connected and the HU was installed in the dash, i pulled the HU and removed the antenna and even replaced the deck, none of these fixed the noise

"Are the underhood grounds in prime condition? At battery, alternator, firewall, engine, etc?"
I have not yet upgraded all of the big 3, but i did replace the battery-chassis wire with no results.

"Did you try disconnecting RCA's at amp? Result?"
Yes, no noise. No sound either lol.
I then reconnected and disconnected at HU, no noise. I used a pair of muting plugs and still no noise

"Did you try running RCA's outside the car? (for test purposes only - obviously)"
No. Unfortunately I don't have an extra pair. What would be the easiest way to go about this as the RCAs are already installed.

Sometimes a ground loop isolator on the RCA's work.
Yeh I thought about that but I still am not sure if it is the RCAs that are the problem.

its a kenwood dpx701

i also used my old one, a panasonic

update: i hooked up a portable cd player to the amps inputs and no noise.
it has to be the HU now. i've already grounded to chassis and powered to battery and the only thing left is to ground the RCAs I can't find any thread that describes the process

anyone? thanks

tried it..it did nothing

i FINALLY isolated the noise. i stole my brothers high grade AV RCAs for his TV and hooked the head unit up to it. NO NOISE. now could someone help me with what the best course of action here is? I don't understand, these are suppose to be high quality double shielded stinger RCAs. should I get new ones or get a filter of some sort. is it possible that somehow when I was installing the RCAs it got shorted somewhere? thanks for your help guys

Try isolating the shield at one or other end. Rather than experimenting with pricy RCA's I have a short male/female RCA with the shield cut. I connect the in-car RCA's through this at one or the other end. If that resolves the issue then cut the shield at the appropriate end of your in-car RCA's.

BTW, congrats on the excellent troubleshooting skills - muting plugs, external MP3 player - you'd make David Navone proud! (I think I just gave away my age  )

"BTW, congrats on the excellent troubleshooting skills - muting plugs, external MP3 player - you'd make David Navone proud! (I think I just gave away my age  )"

hey thanks, it took a lot of time and patience, or lack thereof, to find the problem. i learned a lot though. for instance how many freaking possible things could be wrong here. lol.

sorry for such a stupid question but how do i cut the shield?

ok so i removed the shield and tried this on my old cables, first on the left and then right of my amp-end and then left and right of my HU-end. there was noise each time. does it matter if i only made this shield isolator for one channel?

afterwards i got worried and plugged the other RCAs in and no noise again. i know somethings messed up with these Stinger RCAs. I guess my only option is to take them out and check for a short somewhere. thanks

If the whining noise matches rpm but it is not a ticking noise matching the rpm then more than likely it's the alternator. An alternator generates a/c voltage which passes through diodes to convert it to DC. If one or more diodes fail then a/c gets though which you hear as a whine. All vehicle electronics work on DC so a/c can be inducive to damage. Good thing is that the electronic modules themselves have their own dc/dc converters which help prevent damage.

Temp sensors are resistors and wouldn't suffer damage from tired rectifiers in the alternator. The problem your facing is a mechanical one which goes beyond the scope of this forum.

A simple answer to your query: no