Bought a used Minnkota powerdrive 80lb thrust. It has the autopilot function, and also the co pilot remote added to it. Tthere is a cable coming off the head of the unit that I have been told is supposed to be for fish finder attachment. My question is what type of fishfinder and what functions will it perform? I am in the process of purchasing a new fishfinder and if the minnkota can be used on it that would be a definite plus. Thanks ahead of time for your help.. any and all info is appreciated. (its the small cable coming off the head unit in the second picture.)