Thanks for the help guys but the problem wasn't in the transducer or unit,,got in touch with hummingbird and they told me to check the transducer wire and make sure it wasn't touching or wrapped around any other wires,,,well sure enough it was wrapped tight against the power wire and was causing interference with the readings,I guess when I had the kill switch replaced they must have done it by mistake,,,who knows,,,anyway thanks for the help..