Problem with FishFinder & DepthSounder

[bigbuck]

Picked up the new to me boat this weekend, it's a 19ft Larson Fish & Ski. It's got an older Lowrance X49 fishfinder and a Lowrance 3500 DepthSounder in the dash. Now here is the problem, the fishfinder displays an obscence depth (700+ ft) when there is only a few feet under the keel, the depthsounder does the same thing occasionally. Is there anything I can check that could be a simple fix or are the units pooched???

Thanks.

[Rizzo]

get into deeper water, lots of units don't work well in minimal depths

[bigbuck]

Thanks, but, even in deeper water 30+ft, the same thing happens, all sorts of screwy readings.

[Rizzo]

Is the transducer pointing straight down? On an angle will cause problems. Is it a speed issue? IE going to fast transducer might get above water line. Bubbles from the motor or weeds on the transducer can also cause failure.

[ohhenrygsr]

Check out the angle of the transducer and if there is any obvious scratches or gouges in the transducer itself. Also check the setting on the fishing unit i usually leave mine on Auto Sensitivity. But my best guess is the angle will be off, a perfectly lined transducer will read at high speeds.

[bigbuck]

It's a fiberglass boat, the transducer is shoot thu the hull. When I'm up on the lake next week, I would love to have a couple of starting points and work from there.

[Garnet]

Does it work some times?

 

Put your hand on transducer , should feel it ticking.

 

It might be a 50 for deep water most of these unit you can switch between 50 and 200.

 

The cable can be sensitive to motor interference, know a guy that rapped the whole cable in electric tape said it worked.

 

Could be just weak transducer just match the color of ends and it will fit.

 

Garnet

Edited May 26, 2009 by Garnet

[Slick Willy]

If it's a thru-hull it may not be properly bonded to the hull.

>Bill

[Spiel]

Sounds like interference, are you running both at the same time?

[bigbuck]

After some research, I think it might be interference. I'm going to be taking a good look this weekend at it to see if the transducers are a)close to each other and b)if they are mounted correctly.

Thanks for the replies, it helps to hear advice from those who may have dealt with the same problem.