Old Hummingbird – New Minnkota

I have a new Terranova Minnkota trolling motor and a Helix 7 depth finder with I-pilot and GPS. They are not hooked together, the Hummingbird has it’s own transducer. I recently hooked up an old hummingbird depth finder to the trolling motor to stop getting the “how deep are we” question every 5 minutes.
Problem was the Helix says 4 feet deep and the old Hummingbird said 33 feet deep. Only used it that one time and shut it off, so did not play with it to see if it could be corrected.
What do I need to do to get them both to says the proper depths?
Thanks

Steve,

Might get better response if you add the model # of graph. Also the more detail the better. Terrova generation? Graph to terrova connector model #?

Just makes it easier for the IDO research wizards to help you out.

Just food for thought. I got nutting for help, sorry.

Kurt