Lot of interference with unit transducer mounted on trolling motor when trolling motor is being used. Then clears up when not used.

Install the battery cables to the battery for the gas motor.

Here is a transducer installation guide for Lowrance, this is pretty standard for all transducers. Pay attention to how the boat sits in the water when trolling for level setting to match in water.

http://primus.lowrance.com/icr/units/HDS%20Installation%20Guide.pdf


If you don't have a PDF reader foxit reader is free.


http://www.foxitsoftware.com/Secure_PDF_Reader/

I too have the exact same problem. .6 to 6ft then stays at .6. love to figure this out.

I havew a Minn Kota trolling motor on a Z21 Ranger. Minn Kota has a built in (puck type) transducer on the motor. I have a lowrance 135x on the front. The lowrance will read the temp but will blink the depth. I switched out the depth finder with another 135x with the same results. I have a 522c gps unit networked together and mounted on the console that works fine. Any suggestions on the problem with the 135x?

You can use a thru-hull transducer but a transom mount transducer will always interference with all of that water and alot of air bubbles moving under it at high speeds.

Had the same issue with another brand. Turned out the transducer cable was picking up noise from other cables (power, trolling mtr. etc). Try moving the transducer cable away from any other cables. I put the cable in a 1/4 " plastic housing up to the point where it was above deck and it stopped all the strange stuff. Not sure about the temp issue??

Are you utilizing another unit in your dash? If so, sometimes when both units are on and in sonar mode, their frequencies will intefere with each other causing the vertical lines. I would suggest turning your dash unit off or lowering it's Hertz rate from 200Hz down to 50Hz.

Funny story...I saw this same issue on my boat years ago. I had an X102C up fron and an LCX-19c in the dash. I acutally thought it was some sort of man-made structure and spent time fishing it...DOH!

Did the unit come with a strap to mount the transducer to a bow mount electric? Most units do... If not there is probably one available for the unit as an aftermarket accessory or accessory from the manufacturer... Regarding the transducer wire, just wrap and rout this up the front of the bow mount motor shaft so when you pull the motor up and secure it, it is not going to get in the way. You could cable tie the cord down near the bottom of the shaft and one up near the top where they wont interfere with the motor bracket when the motor is positioned up on the boat.

False fish readings are commonly caused by electrical interference such as alternator noise, and by air bubbles flowing across transducer.

For starters make sure your fishfinder is on an independent circuit and not on one powered by your ignition switch. In other words, you should be able to turn your fishfinder on, even though the engine is turned off. Ideally the fishfinder should be wired directly to the battery with an in line fuse.

Try running the boat at a speed slightly higher than trolling speed, then kill the engine, as the boat slows down to trolling speed do you still see false echos? If yes then the problem probably lies with how the transducer is mounted, or where it is located on the hull.

If you don't see the false echos when the engine is off, it may be necessary to reroute the transducer cable to keep it away from the boat's ignition wires. You can get transducer extension cables if necessary. Also there are filters that you can buy that suppress alternator noise buy attaching between the battery and the engine.

Another common cause of false echos from electrical interference is a transducer cable that has been cut and spliced.

I hope this information helps. Please reply if you have any questions about my response.

It is not recommended to cut the transducer cables as they are sensitive to outside interference.  Most trolling motors have adjustable shafts so you can set it at the depth you want. Look for a locking mechanism where the shaft attaches to the mounting bracket.