Rear windshield washer pump motor

Anyone have an idea on a 2001 which windshield washer fluid pump works the rear window?? I just pulled the fender liner out and see there are 2 separate pumps.........not sure right off hand which one goes to the front and which one to the back.

Turn the key on, hit the switch, and see which one turns on.

The upper one does the rear, the lower the front, so that when you run out you run out of front last.