I helped my friend put in an aftermarket double din stereo in his truck a couple months ago, and after we got it all hooked up we had some interference in the audio. It gets worse when something electrical comes on, like the windshield wipers, or A/C. We thought maybe we had a bad ground, but I ran a ground wire to the engine cab and tried all ground cables behind the stereo and have the same issue.
Yesterday we installed a cb radio in his truck, and the exact same thing is happening in the cb. We didnt tie the cb into anything. Straight power to the battery, and ground to a bolt on the engine cab that the negative on the battery was also going to. Any feedback or info would be awesome. Thanks