I've checked the microswitch - makes and breaks when checked with a multimeter. The bulbs are also OK. Anybody know whether these are fused separately - I can't trace any fuse that supplies them from the diagrams I have? Any other suggestions as to a possible fault?
Thanks in advance.

 

These share a fuse with other functions controlled by Body Processor Module. Are your glovebox and visor vanity lights working? If they are then the fuse and the Body Processor are OK.

If they are OK, then recheck that the switch is really mechanically actuating when the trunk is opened.

If the switch is good, there is a diode module next to the battery that could be at fault, but it would be very rare for that to fail and you are just as likely to have a broken wire somewhere IMO.

 

All I know is that my switching mechanism seems to be delayed, sometimes takes like 5 minutes before it switches; I have sprayed WD40 over it, only helped short term. Opening the boot more frequently seems to help as well. So manually operating it works fine, but it collects some dirt or the grease is drying after a while. Have not found the root cause.
Not sure this helps...

 

Update - thanks for that guys. Searched on line and found somebody had mentioned that these microswitches can show correct function on a multimeter but not actually complete the circuit in real life so I checked mine again and that's exactly what is happening - will show continuity when on a meter but not actually carry current - can only assume that it's high resistance on the contacts, so it is the switch that's faulty. Will try and source one at my local electronics store, if not it's $60 or so via the Jaguar dealer.