[B. W.]

You probably already know this: washer pump is mechanical, driven off the wiper motor, it is held in the "engaged" position by a relay, when the relay shuts off the washer pump is turned off by a mechanical cam ( been a while since I've been into one, I think that's right) Anyway, what I'm getting at is this: if the pump is not shutting off it could be a mechanical failure inside the wiper motor or (obviously) electrical - power is being supplied continuously. If you have pulled ANY power off the wiper circuit it might feed back & keep the washer pump on. I found on one rig the hot wire for the electric choke was tapped into the wiper circuit, the washers would not shut off.

Side note: whoever designed the system was either a mad genius or high on crack!