Like I said earlier, I had a similar problem on my Mini Cooper a while
back whereby the fuse would always blow (in the 4 fuse box holder on the
bulkhead) when the ignition was switched on and I'd end up with no wipers
and no rev. counter and my wipers died in the rain too.  Anyway after much
messing around and head scratching it turned out to be a faulty/worn out
wiper motor park switch that was causing the problems.  So does your wipers
still self-park?  Even so check behind your wiper motor because it does tend
to get wet and mucky and somewhere along the wiring loom the rev. counter is
related to the wiper motor.  Once I fitted a new park switch everything was
fine again.

Taffy