New head unit makes buzzing noise through all speakers.

[Ez007]

As the titles states I've installed a new head unit. It all seems to work well and sounds loud etc, but when turned down low you can hear a buzzing or static sound through all speakers?
My research leads me to think it may be a bad ground? The ground is attached well to the black ground wire in the harness, so I'm stuck on what to try? I can't seem to trace where the black ground cable is actually grounded to the chassis, can I find this without removing the whole dash?
Any other ideas what's causing the buzzing noise?
Ive just purchased this Ford festiva 1995 gli as my first car, and I'm ready to sell it now as the buzzing audio is just not acceptable to me. I'd like to keep the car, but this is a deal breaker.... Help!

[bravekozak]

There are many causes for radio interference.
Do you have a capacitor?

[Ez007]

Hi brave, no i dont what is that? thanks mate

[firebush357]

You could try something like this Inline Noise Filter to see if that helps.

[Ez007]

Thanks, ive read about those but they seem to only work for 50% of people, and ive heard people say it lessens the music output aswell? as a last resort i may try one, but would rather just get a good ground, which from all assessments seems to be the issue. thanks heaps firebush

Some further info

it occurs when the car is not running, so doesnt seem alternator related
it occurs with and without the Ariel plugged in, so i dont think its the Ariel either.
But feel free to correct me if im wrong, im good at fixing computers and game consoles, but this is my first outing with car audio.
Thanks

[firebush357]

Get a self tapping screw and a ring terminal and just make a new ground for the radio. If this doesn't help then try separating your power wires away from your speaker wires, I don't think this is the issue if it does it while the vehicle is off but it is worth a shot. Also is the Head Unit new or used? maybe there is something wrong inside of it.

[Team Lightning]

If it’s occuring with the car not running, I’m thinking it’s a radio issue. If you have a spare battery, try hooking the radio directly to it without going thru the metal in the car. See if it still has the noise. If so, try another radio.

[Ez007]

Get a self tapping screw and a ring terminal and just make a new ground for the radio. If this doesn't help then try separating your power wires away from your speaker wires, I don't think this is the issue if it does it while the vehicle is off but it is worth a shot. Also is the Head Unit new or used? maybe there is something wrong inside of it.

Thanks ill try to make a new ground, if i can find a spot
Also the power wires and speaker wires are coiled together coming from inside the dash wouldnt it be futile to separate them near the harness when they are wrapped together further down the line?

Its a new headunit but it was given to me by the seller of the car, and told he doesnt know how to hook it up, the stock head unit had already been removed.
In saying that it does appear to be a cheapo china unit with no brand name, so maybe it is the head unit?

The harness wires from the headunit seem to be very thin and flimsy, could this be causing the grounding issue?

Thanks heaps!

[Ez007]

If it’s occuring with the car not running, I’m thinking it’s a radio issue. If you have a spare battery, try hooking the radio directly to it without going thru the metal in the car. See if it still has the noise. If so, try another radio.

I dont have a spare battery sadly,
does the ground still work when the car isint running? or does the car need to be on to produce the ground? that would assure me its the head unit if that is the case.

It also produces the humming when the car is running too

Thanks buddy

[Team Lightning]

The power goes thru the ground regardless. Trying taking the battery loose from the cables and run wires directly to the radio since you don’t have a spare battery. What I’m saying is, isolate the battery from the car as well as the radio from the car. If you still get noise, it’s the radio, if no noise, it’s the electrical system in the car. Then check all grounds you can find. There’s several around the motor. Make sure there’s no paint under the connection of any wires going to the body.