Unless youre talking about the side imaging units, the transducers you have for the 520 and hds5 will work with the newer units. If you get the “Ti”, get the head unit only and it will come with the adaptor to go to the blue connection. If you get the one with the transducer, it is a different plug and youll have to purchase the adaptor to use the current transducer. If you go with the SI unit, it will have a separate SI transducer that will mount close to the center of the transom. Some put it under or on the side of the Jackplate, just make sure the motor, when trimmed down, will clear it since they are long. AS to the power wires, the blue connections will work on the new units, however due to power consumption, you may have to wire to the pigtail with larger wires.JohnJones Trolling Motor Services870 773 3474Motorguide/MinnKota/PowerPole/Lowrance/Humminbird
.
