The depth finder transducer is mounted inside the hull in the bilge, in a little molded pocket usually. Mine is near the back of my engine (Ddrive) drivers side. It is a black disk about 2 in dia. and about .75 in thick. It has a black wire coming out of it. It is glued to the hull. Yours may have come loose. It is also possible that one of the wires to the two boxes that support the depth finder (black, about 6" square, mine are under the dash) has come loose. One box has the other end of the transducer cable, the other has a multiconnector plug that goes up in the dash to the multifunction gauge. Check the connections. There is 12vdc and ground wires that are hooked to the ignition (purple) wire near your keyswitch. My connections are terrible, the wiring was done by a very bad mechanic. My depth finder does not work, I need to rewire mine, I'll take pics when I do it.