Had a delve into the innards a couple of months ago. empeg is currently not installed. I did have the blue wires connected. Is this a no-no as in a Ghostbusters-don't-cross-the-streams stylee 'cos ...

I disconnected them and played with the radio position and improved the reception.

I reconnected the empeg and got loads of interference.

I do have a bit of a rash streak so I reconnected the blue wires again and with the empeg connected got no inteference.

At the moment, I have the radio in and a big hole where the empeg should be so I can get to the radio when I get the occassional loss of signal. Something going wrong at the back there somewhere when sometimes something shifts or touches something it shouldn't.

To be honest, I'm amazed that anything I try to install works at all.

My current plan is to try and do a more 'professional' ISO split solution as the one I have at the moment is well dodgy (see pictures from original post) and I want to make some more secure connections.