I have a 2003 Mercury 225 Optimax. I neglected to fill the remote oiltank. It started to use the engine mounted tank (as it should) and as the oil started to get low the 4 beep low oil alarm came on. I stopped the engine and filled both the engine mounted and remote tanks with oil. I thought all was fine. Until later the next week I got the oil alarm again. Remote tank is full, engine mounted tank is being used. What is the trick to get the remote tank to work?