Disco 1 Heated rear window switch light coming on by itself

Hello, I went out to my 300Tdi yesterday and heard a relay chattering without the key in the ignition. The light in the heated rear window switch was going on and off too. I removed the switch and could still hear the chattering. I guess I can remove the relay temporarily but that still doesn't explain where the full-time +12v feed is getting at the circuits. The vehicle was originally fitted with twin socket 7-pin electrics, I've removed the grey socket, pretty sure the remaining wires were left in the drivers side rear inner wing in a terminal block, guess that's where I should start to look as I think there is a permanent +12v feed there? (oh don't we all love stripping out the inward facing seats and the boot trim!). Any better ideas please?

Checked wiring diagram in my Haynes manual and there is a permanent live feed to the relay, will get a replacement and see if fault persists...

Just to complete the story - I got a second-hand relay from eBay (searching using the reference number on the relay body), issue has gone (for the time being!) - one lives and learns