A couple of weeks ago I had to replace a broken gray water gate valve and the connecting base on the pump housing. I disconnected the two wires going to the pump not taking note of which wire went to which connector (black and white coming down and then red and black after the splices going to the pump). I put everything back together and went out for a couple of weeks of travel. I came home with a full tank and went to unload and found the macerator did not work! Motor ran but nothing came out, heard weird sounds coming from the tank. I discovered that there was suction at the hose end! The light bulb came on at that time.....I had reversed the two wires resulting in the pump rotating in the wrong direction. Lesson learned...take note of which colors goes where before disconnecting! All is A-OK now. Ron G.