When I have turned the ignition off my highbeams have remained on.

Bad Multi Function Switch And/or Connector To Switch (burnt)

check relay switch retraction sping or replace the unit

Probably the high beam relay.

What you need is a headlight switch and you can get them at just about any auto parts store.

Check the head light switch.

that is either the headlight switch is bad or a connector on headlight switch also poss the dimmer switch.
check both headlight switch and or dimmer switch one of them is burnt up.

the horn relay is located behind the glovebox in relay center, the highbeam doesnt have a relay, check the bulbs and also check the highbeam switch located on steering column. hope this helps,

bad earth r dodgi indicator stalk

This is the procedure from the service manaul:

JAGUAR
XJ8 Remote Control Programming
1. Unlock the Boot/trunk with key.
2. Turn Ignition on.
3. Warning light on dash comes on.
4. When they go out, lift arm rest, inside their is a valley button, Press 5 times within 5 secs of lights on dash going out, Horn & Lights Flash.
5. Press any button on remote, remote programmed.

The headlight module is a well engineered electronic black box . If you have an electronics
background you can repair it.contact me [email protected] you have difficulty with the
difference between an amp and a volt a replacement is available at your local dealer for
about $150.