Depth finder blinking after leaving no wake speed

[jmalvaso]

This is kind of a long shot, but wondering if anyone has had this issue?
I have a Garmin ECHOMAP UHD 64cv Fishfinder/chartplotter that came with a GT24UHD transducer. The Garmin is connected to the fuse box.

I have this transom mount on the starboard side on my 1999 Maxum 2400 SCR boat with a Mercruser 5.7L

Worked fine for about a year, then the depth started blinking at high speeds and the sonar/fish finder stops working.

What I've done, which has not resolved the issue:
- tested this with another Garmin ECHOMAP does the same thing
- worked with Garmin to change depth setting; manually set range, change frequency, they sent me a new transducer still same issue
- thought maybe a ground or power issue (even though the only function on the Garmin not working is coming from the transducer) so I ran the power and ground straight to the battery
- moved the transducer

thoughts?
Note, live in New Bern, NC just off the Neuse river (brackish water) boat stays in the water, have a diver that does cleaning/scraping. Other boats in area with Garmin units are not having this issue.

[mmwjr]

So it works a low speed or just sitting? If yes it sounds like air turbulence is occurring around the transducer. Is it mounted away from the drive per the instructions. Have you installed anything near it recently?

[jmalvaso]

yep, low speeds and not moving works fine, nothing new and yes it is installed correctly, sent a picture to Garmin when I was working with them, they approved location.

[mmwjr]

I don’t have any more suggestions.

[jmalvaso]

Mike, you posted this in 2021:
With any V hull the transducer if mounted flush will be at an angle which produces an error of the actual depth. The deeper the water the greater the error. You can add a wedge between the hull and transducer but must be of a material that won’t attenuate the beam and as already mentioned no voids in the bond lines between it and the hull and transducer.

To solve my issue, I bought a compatible Garmin in-hall transducer, must have 6 degrees or less. What would you recommend for the wedge? I was thinking of I'd have to get some fiberglass to build it up.

thoughts?

thanks,
john

[mmwjr]

John, solid fiberglass should work but another option is to make it with a cavity in the center that you can fill with a fluid I just don’t recall if it mineral oil or something else. You should do some research on the internet.

[jmalvaso]

Mike,

thanks for the quick response, I'll do that.

john