[philso]

Thanks for your input, Al.

The input voltage to the Spike did not change as the motor was connected and disconnected. We put the probes on the input terminals of the Spike so any bad connections "upstream" would have been evident.

Only the output voltage changed. We may have to try it with a lower current load in case there is some current limiting device in the Spike.

Swapping the PWM cable for another one did not seem to change things.

I can also try to measure the current running through the Spike using my clamp-on meter.