The diagrams in both the 95 and 99 books show the ground wire as black. On the 95, white goes to terminal 4 - park; brown/red to terminal 3 - run; black/yellow to terminal 2 - wash (I think). Terminal one, black, is ground.
Whoever did the schematics for the 99 book must have been on crack. They're cryptic and full of gaps. As usual, the connector listed (C 310, the main harness connector at the top of the liftgate) is omitted from the pinout illustrations, and no connector at the motor itself is identified, although I'm pretty sure there is one.
But anyway, on the schematic, we have # 1, ground, black, as usual. The diagrams are, as I said, not very informative, but terminal 2 bets a black/white, which I believe is the continuous run for the washer. Terminal 3 gets brown/light green, which I think is the intermittent wipe, and terminal 4 gets brown/pink, which should be park.
However, the terminal numbers may be screwed up. The diagram shows no connector number at the wiper motor itself, but four other connectors in line between it and the wiper switch, all with different pinouts. On the last in line, C310, motor terminal #1= its #9; motor #2 = #1, motor # 3 = #8, and motor # 4= #7.
You should be able to sort this out with a test light or meter. Turn on the ignition but not the wiper switch, and whichever wire is live is the park. Turn the wiper switch on, and whichever wire is turned on is for run. When you put it on "wash," that one should turn off, and another one turn on.