Volvo Repair: Volvo 245DL tail/instrument lights/fuse, light bulbs, taillight assemblies

Question
Our 245Dl 1980 Volvo in Australia has tail light and instrument panel light failure. The lower two fuses blow each time I replace them. Nothing else seems to have changed prior to this happening. I notice a slight blackening of the tail light bulbs but they both still work when tested individually on the battery

Answer
Peter, there is a short somewhere.  Most likey its in the taillight assemblies itself.  Roger

Peter, was doing some thinking and I have seen problems in the harness itself going to the cluster.  You would have to ohm out the wire to see where the wire is broken/touching somewhere.  The cluster is easy to pull out but also check your front marker assemblies.  I have seen issues where bulbs fuse together.  Roger