Cobra 29LTD buzz sound

I got a Cobra CB connected in the rig up in the visor top headliner area and used the OEM wire harness. KW provides 3 leads...Switched/HOT/Ground. I used the Switched and ground.

Engine off and sitting in the yard:
All was well until I turned on my dash lites and then I hear a nice BUZZ come out the speaker of the radio itself. It's a steady ZZZZZZZZZZZ sound of low pitch.

Items checked:
1. Ran new 10ga ground wire direct to CB. No difference.
2. Ran new 10ga ground wire direct to aluminum dash. No difference.
3. Replaced dashpot dimmer ($60!). No difference.
4. Replaced all dash 194 bulbs. No difference.
5. Replaced all dash LAMP-ID indicator thingys. Cleaned all connections too. No difference.
6. Disconnected side/tail lights outside. No difference.
7. Disconnected Antenna connector. No difference.
8. Disconnect wire that feeds/powers dash lites. Noise vanishes 100%.

So I am out of ideas here. It's not the alternator since the rig is OFF. The pitch of the buzz changes a bit when you dim/brighten the dash lites...but I can't get rid of it and its really annoying.

I have really good grounds and power. Nothing is corroded (anymore) and voltages are perfect.

There is no noise/sound over the FM/CD radio or speakers. Only the CB.
What else can I do here? - if I had another CB I would try that (different make) just for comparison but I dont.

 

oops...I wonder if I can get a mod to move it for me