Dont have a manual for my 84 Sea Sprite but I have a question regarding the bilge pump. It works fine when I turn it on but is it also supposed to have a sensor for automatic operation or do I simply leave it on all the time or perhaps turn it on every once in awhile when out on the river?<br /><br />Will it be harmed if I do leave it on even though no water may be present in the bilge?