Q: Why does the Zilla cut out above 450 Amps? I have the speed sensor on the Warp 9 motor connected to the Hairball. When I turn on option (a) for single motor speed sensor the Hairball shuts down the input when I accelerate  past a about 450 amps. I then lift up the pedal  and it resets and works again just to cut off again as soon as press past 400-450 amps. I turn off the speed sensor and works fine.

A: Electrical noise on the speed sensor signal sometimes causes the Hairball to shut off power since the noise cancels out the speed sensor input pulses and makes the Hairball think the motor is stalled. If that is the case, turning off option “d” would also make the problem go away. If you hook up your tachometer to the Hairball I believe you will see it drop to zero at high currents or whenever the problem is happening.

Sometimes this can be fixed by better routing of the speed sensor wires relative to high voltage and high current wires since they are the ones picking up controller switching noise.

Another fix that always seems to work is adding a 0.1uF ceramic capacitor* to the speed sensor power wires (red and black) right near the speed sensor. I suggest connecting the capacitor no farther away from the sensor than the connector that came on the sensor.

* The capacitor can be almost any type, Radio Shack PN 272-135, 272-1069, 272-1053 are all acceptable.

I hope this helps,