Re: No windscreen wipers
I am assuming that it only blows when the wipers and/or washers are used, and not as soon as you turn on ignition or accessory. If it blows without using any of these functions, either the voltage feed line from fusebox to wiper switch or switch itself is probably at fault.
To check wiring between switch and motor, disconnect plug at wiper switch, washer bottle and motor to isolate that section of loom. Recommend you get a workshop manual too to check what each line does.
Make sure ign is off so wiper circuit is not being fed voltage. Get a multimeter, but first ensure there is no voltage on any line to be tested - voltage can damage a multimeter when it is set to resistance ranges. (easiest to use a test light to check for voltage - one side to earth, other side to check each pin, should not light up if no volts)
Then set multimeter to resistance, negative lead to earth, use positive to check each pin in plug. Should be open circuit (high resistance) between each wire and earth. If you get a resistance reading, there is your short. Note, I think one of the lines is an earth anyway, so this is where the manual comes in useful.
If this doesn't show a problem, loom is probably ok. Try plugging in wiper switch only again. With ign on, try wipers and washer. If fuse blows, probably switch. If fuse is still ok, connect up washer and motor one by one to see which one blows the fuse.
One thing that often causes these problems is where someone has tapped into the wiring to power an accessory - especially if they have used scotch lock connectors. These are crap, they come apart and can short. If you must tap into a power line, solder all connections and insulate securely - I always use heat shrink inpreference to electrical tape for durability.