I ordered a pressure switch (#W10514214) and when I went to install it, I discovered that the connecting pressure hose had chaffed badly and had a pin hole leak in it. The chafed hose wasn't visible from the top and only discovered after I removed the back cover from the washer. I replaced the switch and hose and that fixed the problem. The real problem was ONLY the leaking pressure hose, but I decided to keep the pressure switch anyway.