I've installed a JVC Head Unit and would like to have the power directly connected, not requiring the key to be in the ignition. It won't keep any of my pre-programed settings the way I have it wired now through the original wiring diagrams I was able to locate.

I've thought of tapping directly into one of the fuses on right side fuse box since it is the easiest box to route wires to. Any ides of a good fuse I could splice into? Any other suggestions are appreciated. I had spliced into cigarette lighter hot wires on other cars in the past.

 

Not sure of the year of the beast.

Jaguar have used "Solid Brown" as direct battery power for a long time.

The XJ40 should have a "solid brown" wire in the OE loom at the stereo for the memory function of the OE stereo????. Our 1987 3.6ltr did, simple as when I did the swap for a Pioneer head unit. That was a looooong time ago, so clear memory, I wish.

The X300 was simple also, so I really do not think that there is an issue with that supply wire AT the stereo opening.