Am I understanding you correctly you can disconnect the wiper motor and fuse still blows? and which relay have you disconnected?
Here is the complete wiring schematic for your system.
You have 3 relays so you will need to disconnect all 3 to see if fuse stills blows to try and isolate the shorted circuit.
The relays would be in the under hood fuse panel.
Just disconnect all 3 and see if short goes away and if it does hook each one back in one at a time and see which one causes the short. Then we can try and isolate the circuits.
Do you have a circuit breaker you can use in place of the fuse so you won't go broke replacing fuses? Do you have a couple of jumper wires? do you have a test light or voltmeter?
Ok then the white and black wire is most likely chaffed somewhere and touching ground. First go to connector C158 see it on the right side near top of this pic
Here is a pic of the connector
The wire you are looking for is pin 38 circuit 950.
You should be able to remove all the relays then take your voltmeter or get you like a headlight bulb or a turn signal bulb. This would work best. Take a couple of jumper wires and hook one end to one side of the bulb then to the battery positive cable,then hook another jumper wire to the other side of the bulb and then hook it to the non power side of the fuse(the side that feeds the wipers). If it lights you have a short to ground. If it does light then go to this connector and disconnect it and see if the bulb goes out. If it does then you problem is after this connector if it doesn't then it is between fuse panel and the connector. Or you can use your meter and hook positive to battery power and ground to the blk/w wire and see if you have power with the connector C158 unhooked.