Unfortunately I think it's the transducer. I have been through so many. I think Lowrance is having some quality control issues. I love their products, but having to glass in 3 transducers into the hull of my Triton is tiring. They will straighten it out hopefully.

I would test it with the other transducer to be sure, but it sounds like you have a bad one after switching units already.

My temp is out at the front of the boat for the second time this season, and I think my 3rd thru-hull transducer is going. Maybe they will learn their lesson like OMC should have.

Good fishin',

Tyler