I have two transducers and cannot tell which one does the speedo. Someone unmounted them and just let them drape into the boat. I want to test them somehow and see which one is for the speedo. Any ideas?
Right now the speedo does not work.
Lastly, if I detemine the transducers are bad and cabling, can I just buy any transducer or does it have to be perfectly for the speedo head?