Hi i have a jaguar xj8 v reg wants happen i tuck the j gate out and the stereo put them all back in now when i turn headlights on my dash lights go out turn the headlights off my dash lights come on plus the stereo illumination lights dont come on what could it be

Stating the obvious I would go back & check all connections from where you were working.

Yep, retrace your work, the J gate is on the CAN network and VERY fragile. If one wire is damaged on that board then problems occur. I suspect the dash cluster or IPK is telling you there's a fault on the wiring at the centre console, the IPK also runs on the CAN network.

You might want to check the dash light dimmer on the side of the steering column. If in working around you may have inadvertently set it to full dim. When the headlights are off the dimmer doesn't come into play. When lights are on the dimmer adjusts the instrument panel lighting