Interference in CB and radio when engine is on

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

 

Anyone?

 

Maybe try a different ground location

 

Whine that increases with engine rpm? Alternator
Static that increases with rpm? Spark

Alternator whine can be cleaned up with a filter.

Spark noise fixed with resistive core wires. Better shielded coax to antenna may help, different path to run antenna may help, but the antenna is picking up the rfi generated by the spark.
However my 2013 has direct connected plugs to the coils, so I'd be screwed as for changing spark plug wires as a solution.

My factory radio does have some whine with the wipers on, ESP on AM. Considered a filter for the wiper motor, but then I don't use am

If you have a ham radio shop nearby, see them re a filter. Goes between alternator output and ground. A good car audio shop should have them too. Also filters to put on power wire at the radio are available.

Start there. Spark noise is harder to address, though they may have some ideas.

 

You want to run the power wire straight to the battery and have a ground no longer than a couple feet.