Release the top from the windshield and push it up.

Walk around to the passenger side.

Look between the first and second "hinge" spots in the top, about directly above the door handle, you will see a small switch with a plunger that is extended (because when you push the top away from the windsheild frame, the switch is "relaxed"). This switch is wired in series with the one in the trunk (the "divider" switch), they both must close in order to allow the pump to run.

There is also a thread here where James11549 provides a picture of the switch, but if you look, you can see it ONLY WHEN THE TOP IS RELEASED FROM THE FRAME!