The USDM Mazda Protege never came with the windshield wiper fluid sensor. Since it's an option I didn't have, of course I wanted it. The wiring for the sensor is already there. You just have to run one wire, add a bulb, and install the sensor into the windshield washer fluid reservoir.
I had to remove the bumper to get to the reservoir. Then I removed the reservoir and drained it and cut a hole in it for the sensor. The hole I cut out looks good, but there's no way I can cut a hole to the tolerances that Mazda did. So I added a bit of silicone to where it is attached to the reservoir to make sure it wouldn't leak. Like I mentioned before, the wiring is already there. I plugged the sensor into the plug next to the reservoir.
Now the fun part.. wiring. I had to install a new wire. I plugged one end of the wire into the dash harness next to the fuse box. This is where the windshield washer fluid sensor wiring that is pre-installed ends, at least for the USDM cars. I ran the wire to the instrument cluster harness and added a bulb for the warning light.
Original installation December 2011