Lowrance LST-3800 Flashes when doing 20+ mph

[Im Lon 2]

My depth finder Lowrance LST-3800 flashes, when traveling 20+ MPH, and when the water depth is over 25' (or at least that seems to be the 2 key factors). If I slow down it reads fine, and if the depth gets below 25' even at 20+ MPH it seems to work just fine.

It is a through haul, and sits right behind the engine on the starboard side. I have tried wiggling it and it seems very secure, no movement at all that I can tell.

What other things should I look for or try in order to help fix this issue?

Any help would be greatly appreciated.

 

[Silvertip]

Very likely and installation problem. What did you use to secure the transducer? Is it near a row of rivets or in line with something beneath the hull that causes turbulence. Transducers cannot read through air and that includes air bubbles and air trapped between the transducer and the hull so take that into consideration.

 

[Im Lon 2]

It came with the boat when it was new in 2008.

 

[Alumarine]

Did it ever work well?

 

[Im Lon 2]

I purchased the boat last year. It has not work right since the day I got it.

 

[Silvertip]

It came with the boat when it was new in 2008.

The fact that it was original equipment means nothing. It could still have been installed improperly.

 

[Im Lon 2]

Should I try and remove it and resecure it? It's not the easiest to got to. Thought about buying a new transducer and installing it depending on cost.