I have a 98 XJR. My side lights have gone and the bulbs appear to be ok as do the fuses. The interior instrument lights (elec windows, centre instruments,clock and rear mirror clusterNOT the speedo) have also gone but only when the side lights or head lights are on. When on full beam the side lights and the instrument lights work again.

Is this a relay problem? wiring? something to do with the light stalk on the steering column?
Any suggestions would be appreciated on trouble shooting this problem...

thanks
Rowan