bulb failure
 

Hi Guy's
I have a 2004 3.2s boxster 34k mls and has never let me down until last trip out.
Car is like new but I noted all my instrument lights went out whilst driving (intermittent at first). I note the instrument cluster (IC) and rear number plate lights (NP) are on same fuse.
Fuse is ok. I have 12v at the NP. If I remove the 2 bulbs from the NP the IC is fine - the dials light up and the bing bong sound is fine. If I reinsert the bulb to the NP it glows very dim and the IC and sounder are not working ??????????????

I have no cct diags for this or knowledge of the wiring - has anyone got any tips or should I simply track down an auto elec in the manchester area to try to sort. At present the NP lights are disabled and all seems fine ?.
Appreciate any help on this as the finances wont stretch to a visit to porsche at present.

regards
Paul Reade
paulreade@tiscali.co.uk