My water gauge on my 1994 440 is pegged "full" no matter what is in the tank. When I disconnect either lead wire the gauge goes to over "full". I unscrewed the cap on top of the sending unit on the tank and there is an oil reservoir that is only half full or so. 2 questions....what is this oil all about and what type is it and could it be the reason my gauge is inop?? wishfull thinking !!
Rip out the old stuff and put in a WEMA gauge and sender, good stuff, got 6 or 7 on my boat. (No, I don't have stock in the company) Fuel, Water and Holding Tank Level Gauges by WEMA USA, Inc.