I have a 2013 5.0 STX 4x4. Has had static since I got it. But would never do it for the service guy under waranty. I even swapped the head unit but no change. Does it with a cd or am/fm running or not, all speakers. Cant find anything loose and did the self diagnostic test. Any suggestions ? the amp is in the radio correct ? Thanks

 

I would have already gone aftermarket, both HU and speakers. I'm assuming you have a low end system in the STX? Much easier to swap those than the stupid luxury radios.

 

Does it do it at night only? I've noticed that the HID ballasts "sometimes" will interfere with the radio performance big time!

I agree with the above...its cheaper jsut to upgrade IF the radio is actually bad

 

Does it all the time. Truck is stock, low miles. Swapped radios no change. Yes low end system.

 

Have you checked connections at the speakers, by any chance? Some have had issues with the connectors in the doors.

 

See what is plug into the cigarette lighter. Mine gets static when I am using them. Not suppose to, but it does.