I’m assuming you have the Empty / Auto actuator? If that’s is a true statement, I would spend some time looking at your actuator, because I had to replace mine. The first step is to make sure you moved the actuator lever far enough, kind of like a detent click. If you’re confident you have moved the lever as far as it can go, I’d temporarily remove it out of the boat, disconnect the cable, and then use your pliers to move the cable in/out from this end for observation of valve open/close