Does anyone know a suitable fuse to piggy back on for connecting a cam, needs to be switched live so the cam only operates during driving/running of engine. Other threads have mentioned F52 as cig lighter, however my F52 is the radio/headphone. I also tried using F55 (cig lighter) however this gives me a permanent live with piggy backing BUT the lighter socket is dead.

I have replied to your PM

Some circuits stay live until the car goes to sleep. Ignore others' fuse numbers as fusebox layout changed (was certainly NOT the same between my 2009 and 2013 cars). Use trailer fuse for permanent live and cigar lighter for switched live.

Re dead lighter socket, you have probably already checked but still worth asking ... the fuse isn't blown, is it? Current: Volvo XC90 T8 Inscription Pro PHEV with some optionals on top
Gone: MY16 RRS2 3.0 SDV6 Autobiography Dynamic, Carpathian Grey & Santorini Black Sliding Pano/Ebony & Ivory 2 Tone
Gone: MY13 RRS 3.0 SDV6 HSE Black Edition, Orkney Grey/Ivory
Gone: MY09 RRS 2.7 TDV6 HSE, Santorini Black/Almond

Sorted

Big thanks to fkarim for his PMs