I screwed up and powered my cb bass acwards 😡

[KF0AWL]

I have a Sears Road Talker that I was testing and I made a major screwup.
The only power plug i could find was exactly backwards from what I needed. (The only way it would fit was black wire + red wire - had my fuses in place wired it up and POP from the CB 🤦🏽 I Flipping wired it red to red black to black checked my fuses not blown' fixed my wires the right way it still powers up but now let's out a high pitched squeal.
Any suggestions what I need to look for or did I fry it? 😞

 

[tvengr]

If the radio was grounded to the car body or through the antenna, there wouldn't be any current flowing through the fuse. That would explain why the fuse isn't blown. It also means that you were applying negative voltage to the radio. If there is a reverse polarity protection diode across the power input, it is probably blown and you probably have some burnt foils on the circuit board. If there is a large value electrolytic decoupling capacitor on the input, it probably exploded and there is nothing left but the leads soldered to the circuit board. If a decoupling capacitor is open, that can cause the radio to break into oscillation and cause the squeal you are hearing. Does the pitch of the squeal change with adjusting the volume control?