Headlamp relay buzzing with Car off

[Underdriven]

Hi, I am having a issue on my 01 IS200 where the headlamp relay under the bonnet is buzzing with the car OFF, headlamp switch at any position including auto, the headlamps dim when the relay is buzzing, lights work as normal with car running. I have removed the plugs from my theft ECU and it still buzzes, another thing I did that has me confused is disconnect the plugs in the driver AND passenger footwells one by one and it STILL buzzes. I do have a aftermarket windscreen (starts with Plinkerson or something like that, I know these are the bad ones), I did notice a bit of moisture on one of the white plugs in the driver footwell but as I said, even with it unplugged the relay still buzzes, I have read A few posts on this forum and tried it all including replacing the relay with a known good one so looking for last opinions before I take it to the shop. Appreciate the help.