K8023 control wires

I built two k8023 kits for an underwater ROV I’m building and was just wondering if it would be possible to use three wires to control both boards. In other words, can one of the wires be used as a common?

Another question:

I’m using 4 twisted pair from a cat6 cable inside tubing for tether and after checking the buoyancy I might have to add one more 24ga wire to achieve the right weight to be neutrally buoyant (I’ve stripped the cables covering off and am just using the wires). I plan to use one pair for 120V ac, one pair for video using baluns, and the last two pair for the control boards. If I could get away with using three for control insted of four, I’ll have one more pair to use for something else.

The question is…do you think I’ll have a problem with interference form the ac power, control signals and the video? There will be no shielding but the wires are twisted.

Thank you, Bill

I can only answer for the control wires,
These must be 1 pair wires each, the ground (GND) can not be used as comon, since it is used for data sensing.

We have no experience with the interference issue.
It has never been reported…