Question about auto bilge function

After doing a search of the forum, I believe that I have the pump with a microprocessor in it but I'm not sure. It's a 1991 SN, but I don't see a float anywhere near the pump.

The problem is that when I turn on the auto bilge switch, the pump runs and runs and runs and pumps the bilge almost compeltely dry but it will keep running until I turn it off. I'm afraid to leave it on auto for fear of burning up the motor.

Any ideas if something is stuck or dirty making it "feel" resistance and thinking it is pumping water?

Thanks for your help.

Great question as my 1990 SN is doing the same thing, will start but not stop.

So in essence it stops when it doesn't feel any resistance against the vanes from being submerged in water?

I did pop mine out of the strainer to look and the strainer had some dirt around the edges. I will get in there clean it out and look at the motor unit itself to make sure it is clean, maybe blast the output shaft with some WD40 to clean it up if I can see and get to it.

I did read that they are designed to not burn out from continued dry use, but just don't like the idea of it running and running and draining the battery at the same time.

I will let you know how I make out.

Thanks.

Thanks for your replies! I'll be back in Indiana on Labor Day weekend and will give cleaning it out real well a shot.

Not to get off topic, but Lakeside, I see in your profile that you replaced your fuel sender unit. What prompted that? My fuel gage jumps all over the place. It somewhat indicates an approximate fuel level but it continuously bounces between 1/4 and 1/8 of tank either direction randomly. It's not too bad when it's full but 3/4 of a tank or under it goes nuts. I checked the ground wiring and connections on top of the fuel tank and even replaced the connectors but no luck. I didn't have a volt meter with me at the time so I don't have any more info.

Dave,
Was the float of your sending unit cork by any chance??