Well, the two plugs are the same, it's basically just a splitter. There is no separate controller it's all contained in the single sensor. But it did come partially assembled, with one side, the sensor, being already plugged in . And the pump was connected by myself. I did add the siphon break, but that's not the issue, it's not turning on at all. The sensor part has a blue indicator light that is on when the pump should be filling. Which in my case, is on but not filling. When I lower I sensor like it "filled" the light goes off indicating it stopped the pump.