driving 2 12v 2A DC motors with Mega

groundFungus:
I think that the sensor is wired like this:

OPTO SENSOR.jpg

Google "Optical Infrared Water Liquid Level Sensor " and this is a common 4 wire diagram.

Wouldn't that mean that I would need some resistors off the yellow and red wires before going to ground? Im new to reading schematics and the like.