Motion sensor light stays on all the time?

I installed a motion sensing light in my horse barn on the inside, with the sensor pointing straight down so when the wife walks in at night, she can see where she's going.

Problem is, the light stays on all the time, regardless of light/dark. I noticed that instead of turning off, the lights dim, but don't turn off completely. When I walk under the light and trip the sensor, the light gets to full brightness again.

Here is my set up....

I have a 14-2 power wire coming in, black, white, bare ground.

The lights (2) each have one black and one white wire.

The motion sensor itself has a black, a white, and a red wire.

All the white wires are connected, the 14-2, motion sensor and the 2 lights.

The black wire from the motion sensor is hooked up to the 14-2 black wire.

The black wires from the lights are connected to the red wire from the motion sensor.

What's wrong with this set up?