Though the transducer ticks continously when the depth finder is on, I will doubleckeck the wiring, as the PO was less than meticulous in his wiring practices, most of which I have cleaned up. I believe the problem with the in-hull transducer is its placement, as the original through-hull transducer is right on the keel-line, just forward of the keel, while the replacement transducer is mounted off to the starboard side by about a foot, so is angled both forward and to starboard, and it doesn't look like a good angle for the beam. Thanks for the response.
Anyone else out there familiar with the original through-hull transducer not being mounted in a through-hull tube, but directly sealed to the outer hull? I remember a post talking about using two pipe wrenches and a length of pipe as a "persuader" to get it off the outer hull. I would guess they use 5200, and the release agent might help, but any direct knowledge would be appreciated. She's on the hard now, so I can barrier-coat and anti-fouling paint, so it's a good time to deal with the transducer.