fuse blows

[big pants]

my mum has a e reg merc camper near side back light dont work and also front light dont work and dash dont light up.its all on same fuse. when we repalce it just blows the fuse.there has being water getting in back light lens which we dried out but still cant cure it can anybody help thanks for any reply

[stanleyman]

There could be a fault at anyone of these lights and possibly also the numberplate light. I suggest taking them all out and disconnect, then put in a new fuse, if this stays ok, replace each light until you find the faulty one. Check for short circuits to earth, loose and bare connections. If the fuse blows with all lights disconnected then the fault is probably in the wiring.