Buzzing noise from car speakers

[Parnicalnrd]

I have an aftermarket mp 5 in my car fitted with original iso connector and i have a buzzing noise from the speaker only when the engine is on.Can anybody help me?

 

[bazzabear]

Does it change pitch with the revs of the engine?

 

[Parnicalnrd]

No.the noise starts when i turn the key on the phase 2!

 

[bazzabear]

Hmm, not sure then. I suspected it was interference through the aerial, but that usually changes with engine revs so it's really obvious.

 

[KillerHERTZ]

Possibly a dodgy earth somewhere...

 

[Parnicalnrd]

It changes with the revs as well now

 

[grober]

https://www.lifewire.com/whining-noise-when-i-use-aux-input-534592

LOOK FOR GROUND LOOP PROBLEMS. - may be soved by use of a Ground loop isolator.

 

[Parnicalnrd]

I don't have any amp connected and the ground loop has rca inputs and my only rca is the reverse camera one

 

[bob6600]

Possibly a dodgy earth somewhere...

I would guess at this.