The "Park" switch is located inside the wiper motor assembly, but I can't find a circuit description to determine how to diagnose this system. There is also a computer circuit with an "auto-off" system inside the wiper switch. That means either the switch or the motor can be causing this problem.
We may be able to figure this out if you measure the voltage on the blue / yellow wire at the motor. You should find 12 volts on that wire but it will be switching on and off while the motor is running. I can't tell from the diagram if the 12 volts will be there when the wipers are in the "park" position or when they're not in that position. You can use a digital voltmeter to measure that, but for this type of test, a test light is easier and faster. If you see that voltage switch on and off while the motor is running, suspect the wiper switch or a broken wire going to it. If it stays at 0 volts, suspect the motor.
Jun 2, 2015 at 9:46 PM
