High pitch screech thru speakers

[imjustjack]

Screeching noise through my tower speakers when I rev the engine or when I turn battery switch to the 2 position. The screeching hi pich noise comes thru the speakers even when stereo power (Battery) is off.
Anybody?
Thanks.

[Wylietunes]

If any stereo gear has been added, then focus back on that instillation, specifically its B+ and B- terminations.