[cj847]

Grasping at straws, hoping a true expert is out there.

I have a custom autosound radio and a small 4 ch Jensen amp and a Rockville under seat sub.

Sounds great with engine off. When running, I have a whistle that changes pitch with engine RPM.

I have searched the internet for a solution. I have worked thru all kinds of checklists. I have watched dozens of "expert" videos. Nothing works.

I have:
-LS swap
-4 ga power and ground
-1 ohm resistance to ground from amp to battery
-grounds battery to motor, motor to frame, motor to cab all clean
-grounded the head unit to the battery to insure a perfect ground
-power to head unit is direct from fuse panel AND has a filter on it
-RCA connections have filters
-bypass the amp, still have the noise
-bypass the head unit (ie bluetooth adapter direct to amp) still have the noise
-move the bluetooth adapter all around the cab, still have the noise and does not even change pitch.
-had a spare alternator so I changed it. didn't help
-changed the spark plug wires, didn't help

Any ideas? Thanks in advance.