HU-850 and 12V Sockets not working.

[tufty67]

Hi Folks, I have a 2005 (facelift model) V70 D5 SE. A few weeks ago the HU-850 and the 12V sockets in front and rear would intermittently turn off and then reappear a few moments later. They are now both permanently off. I have checked all relevant fuses and they are fine and also the wiring at the back of the HU-850 which is also okay. There is power going to the HU-850 and it will eject CDs but the display is blank and no sound. There is continuity from the 12V socket bodies to earth but no live when ignition is on. Any ideas? all help very much appreciated.