Here is our schematic of manual prop control relay board. Relay board switches the 4 wires coming out of the controller, and relay coils source power from controller input.
Have set up so if one relay sticks closed, or both fine and course switches are pushed at same time, an open occurs and motor stops and no smoke is let out of controller or relay board.
Since we don't really know what's going on in controller, it won't hurt that wire length of harness and wires used going to relay are exactly that used in factory harness as compared to lengthening.
Y10-06-11