All modes dead all of a sudden. Washer spray still works. Back wipers still work. I have replaced the green 30A fuse in the dash with a replacement one found in the engine fuse box and it did nothing. Any advice on where to go next?
Well, you've already tried the first thing I would have tried, given what happened to me. Now, if the spare fuse you grabbed had also been sitting in the car's fusebox for 14 years, maybe it's worth applying an eraser to its blades too. But that's probably a long shot, as often just pulling and reinserting a fuse will scrub enough tarnish off for stuff to happen. So if tarnished fuse blades wasn't it, a person just grabs a multimeter and goes seeing where the 12 volts are and where they aren't, according to the diagram, and then does the needful. As all the modes are dead, I'd probably start by checking for IG-ON voltage at L48 pin 2 at the wiper switch, and if not there, L87 pins 4 and 5 (L87's in a pretty surprising place, far right end of the dash, you might see it by removing just the triangle-window trim there), or 2A pin 11 at the under-dash fusebox. And, of course, check the ground connection at the wiper motor (A35 pin 5, A56 pins 10 and 8, screwed to the body at ground point A3 at the left inner fender). A56 is under the left end of the dash, not high up. If there's power at L48 pin 2, and a good motor ground, then check if power's at L48 pin 3 with low speed selected, and pin 4 with high selected, and pin 1 (intermittently) with intermittent selected. And if it is, check those again at pins 6, 5, and 12 (respectively) of AL4 (that's high under the left end of the dash) and pins 1, 4, and 3 (respectively) of A35 at the wiper motor. Toyota Service Information and Where To Find It | PriusChat
Thanks for all the information, ChapmanF. I'll get a multimeter and try to work through all this. Much appreciated.
On my car the symptoms weren't exactly the same. My wiper motor would hesitate, sometimes fail to work, sometimes not, and pushing the wipers a little would often get it to work for a while. In my case the motor was failing, so after putting up with imperfectly working wipers for a while, i bought a wiper assembly from an ebay seller and replaced the motor and assembly together. Not sure if you have a bad wiper motor, but it seems possible.