I believe what he is saying that he has added an amp to the stereo and since it is not very well shielded from the cb RF he is getting feed back thru the amp to the external speakers. The only way around that is a relay connected CB TX switch to turn rhe power to the amp off when the CB transmits or to physically turn amp off when he is using the CB.
w, your rite, unplug amp, it works fine, amp on, it comes through speakers , but transmits also, last nite it sounded like it had feedback, through the speakers.can u wire amp into pigtail under seat, its near left rear passenger seat? has boot over it. also if u turn radio off it makes noise through speakers when u key the mic.