I reported a flat battery some time ago and blamed the Sony radio as I thought I hadn't switched it off properly. Went to van last week to find we had dropped from 12.9 to 9.6. Replaced battery and as i connected heard the radio brrrrrr- cd player?. Disconnected everything and started again to find that radio actually flashed up. How do I switch the blasted thing off? I've removed it from the van as a temporary measure. In testing the system I noticed that the terminal sparked except when the fuse for the battery is out. With no EHU and the master switch off why is this circuit still alive?