See you found the ferrite cores. Another thing that helps is a ground wire from cab frame to radio housing if the housing isn't bolted to anything grounded. I also replaced the stock antenna with a cheap aftermarket one. Apparently it gets a stronger signal which helped with static. I have 6 cheap LED's and very little noise just with aftermarket antenna and ground wire to radio housing. I also ran the antenna wire on opposite side from wiring harness and crossed the wiring at light switches at a right angle.