High pitched noise from stereo

[ukrkoz]

Hi all
I have high pitched noise, changing with RPMs, coming from stereo speakers. It is on and off, sometimes louder, sometimes quieter. SUPER annoying. No noise when stereo is turned off. Started about 6 mths ago.
Thank you

 

[intheburbs]

Interference from the ignition system. First thing I'd do is check/replace your plug wires.

 

[ukrkoz]

Wires are new as of just over a year.

 

[Joseph Garcia]

Is your stereo OEM or aftermarket?

Does the noise come from all 4 door speakers at the same time?

 

[tom3]

Used to be a problem with alternators doing this but usually with aftermarket stereos. The fix was a filter in the power supply line to the stereo. Any changes in your sound system?

 

[ukrkoz]

Stereo is OEM.
BT added about a year ago but it was all fine untill recent.
Alternator is OEM.

 

[Fless]

Check underhood ground wires. The hood should be grounded to the firewall and there are several others that can contribute to lack of shielding.

 

[ukrkoz]

So, check all ground straps?

 

[Fless]

Straps, cables, anything that should make a ground. You could experiment a bit with jumper cables, with one end on a good ground and moving the other end to various locations on the truck.

 

[Joseph Garcia]

Stereo is OEM.
BT added about a year ago but it was all fine untill recent.
Alternator is OEM.

What is BT?