I have an 18' Fiberglass bass boat, the boat original came with a flasher/sounder with the transducer mounted to the hull with apoxy. This year I purchased 2 new Humminbird finders one for the bow and one w/ GPS by the cockpit. So anyways I purchased the hull transducers from Humminbird and installed them, using there instructions and now I've got 2 transducers epoxied to the bottom of my boat and neither work? So my questions is has anybody every had this problem? What should I do?