Long-time member hobbit described the thing pretty thoroughly here (in the context of building a hack to control the blower while the car is off, for camping).
You can't really test the blower controller that way. It has to be connected like it was in the car- power, ground, and control signal (variable duty cycle squarewave) going in, and a load (blower) on the output. Then see if it works. Posted via the PriusChat mobile app.
In a pinch you might use something like a headlight for a load. I see in hobbit's write-up that about 5 kHz works for the control signal, and more low time in the duty cycle translates to more output. Pinning the control input to ground could be an easy way to get max output for a quick test.
I've now realised how stupid I am. I was talking about the hybrid battery controller and thinking it was the same as the A/C blower controller which it isn't. It's the black one in there
