The controller didn't get damaged - I checked voltage was working remote operated before doing the rework.

I'll check the gate voltage next. The info I browsed for FETS indicated current coming in on source, leaving on drain, controlled/modulated by gate.

It was all wired in this fashion except that instead of + it was all wired to ground instead. So the gate is wired to an IC whose PIN 1 is wired to the ground plane.