I think there is a relay in there that maybe sticking you may have to just clean the wloe thing. You can use a volt meter to see where the power leads goto and if it is going through the relay once you have the float attached and check the switch as if it got changed by acident then you have to use the other switch input location or just switch it back to the original mode I believe it should be in mode a and the sencor in sencor 1.

Bill