Front Sonor Trouble

G-Ko · Post by **G-Ko** » Tue Mar 17, 2009 1:13 pm

Alright.. So I think I have tried everything, but wanted to see if anyone had any suggestions or solutions for me. I have two lowrance units n my boat that I do run at the same time. I have the 37c up front and the 28c-hd on the console. I am having trouble with the unit up front and don't know why.

The front one (37c) doesn't read the depth and always will lose the depth quickly if it finds it for a few seconds. I first thought it was a software issue, so I upgraded to 2.4 but it hasn't helped. Then I thought it was the interference so I tried with only the 37c unit on, but that also didn't solve the problem.

I have the unit on the universal transducer from Minn Kota. Is that the problem? Do I need to get a transducer just for the trolling motor and forget about the universal sonar?

I know that the units will get some interference when both are running, but why can't my unit get any reading? Any ideas? If I need to check the unit or motor, where can I have that done?

Thanks

Greg Kosich

skeeter195 · Post by **skeeter195** » Tue Mar 17, 2009 1:48 pm

I'm having the same problem with my 520c in the front of the boat with the lowrance transducer. Wish I could help if I figure it out I'll let you know.

Nunyo Bizness · Post by **Nunyo Bizness** » Tue Mar 17, 2009 2:02 pm

I have also had trouble with the 520c. I changed the transducer, but it slowly came back. I would like to hear if anybody else is experiencing this as well.

Yoz

Mark-C · Post by **Mark-C** » Tue Mar 17, 2009 2:31 pm

I went through the same problem. I have a Minn Kota 101 on the bow with universal sonar and a Lowrance LCX15 up front. The interference gets much worse when I step on the trolling motor. Minn Kota and Lowrance were useless in solving the problem. They offered an extra ground wire to install on the trolling motor batteries that did nothing and a few other suggestions that didn't help. I finally gave up and took it to Sunny's Electric Marine in Sac. The fix is to install an internal ground inside the trolling motor and possibly replace the trolling motor armerature if it is a certain type. The catch is that the effectiveness of the fix is variable. It may only help a little or it may help a lot. In my case, it got rid of 2/3's of the interference and my bow sonar can lock on the depth more consistently but its not perfect. Apparently the manufacturer's know there is a problem but they don't seem to want to take care of this. It was definately worth having Sunny's perform the work- I think it was somewhere around $150 or $175- can't remember. There is some possibility of it being covered by warranty but in my case it was not. Hope you guys can get yours taken care of....

Rob Hernandez · Post by **Rob Hernandez** » Tue Mar 17, 2009 3:59 pm

Every Lowrance graph I have ever had has done that weird deal where it reads 300 ft. in 15ft of water. And I've heard all the possible causes just like what you guys wrote about the ground and back and front units on at the same time. Then I've had stretches of time when the units worked great! The best I have encountered was to get the power to the graph from the crank'n batt. or an isoltaed battery and then making sure to not to let the wires to the graph lay on or near the the trolling motor power cables. Then for running your transdeucer cables from the trolling motor itself use a rubber spacer preferably 1/4 inch thick or more between the transdeucer and the motor. Then take some black tubing and slice it length so you can encase the transdeucer wire, then you can ziptie to trolling motor shaft. That was the best no-interference I've ever had.

good luck!

619 · Post by **619** » Tue Mar 17, 2009 5:27 pm

will it work okay with just the front unit on?

gavin8 · Post by **gavin8** » Tue Mar 17, 2009 5:45 pm

It's been my experience that you can't run both units at the same time. The sonar signals will distort each other making them read incorrectly.
I have a x135 in front and a 520c on the console. When I forget to turn off the 520, the 135 freaks out. Once off, the 135 works fine.

G-Ko · Post by **G-Ko** » Wed Mar 18, 2009 12:28 pm

I have tried with just the front unit on only, but that hasn't solved my problem. I guess I will have to play around with the wiring.

Is this only a lowrance problem, or is this also a problem with other companies, like humminbird?

Would still appreciate any suggestions to the solution.

Greg

Noluk · Post by **Noluk** » Wed Mar 18, 2009 12:56 pm

Are you runningn the sonar with the trolling motor up. If a sonar unit gets stuck looking for the bottom 300 feet down it will ignore the actual bottom reading at 15 feet as surface noise. Manually setting a depth range or turning the unit off and on usually corrects this. (the interference problem is a different cause) Sonars rely on sound echoing. The sound can bounce from the tansducer to the bottom to the surface of the water back to the bottom etc several times. This is what causes the confusion for the machines.

Try manually setting the depth range to a suitable level and see if your unit tracks the bottom again.

Ken C. · Post by **Ken C.** » Wed Mar 18, 2009 8:41 pm

You should have the TM batteries grounded to the cranking battery for starters (that is, connect the ground of one TM battery to the ground of the cranking battery).

Also as mentioned make sure you don't leave the front sonar running when you pull up the TM as that caneate problems.

Depending on the depth of the water your front sonar can actually pick up the pings from the rear sonar and vice-versa. Turn one off, change the ping interval, change the sensitivity, change the frequency (if possible) toattempt a fix.

I have read about the universal X'ducers causing problems, and I have heard about folks placing a small piece of thin lead sheet between their puck and the TM housing to cut interference.

doug77 · Post by **doug77** » Thu Mar 19, 2009 4:24 am

You might try a ferrite filter($5)on the ducer line.You can leave a fax number at my shop and I will fax you a list of stuff to check that I made up-Doug Ocean Aire Electronics805-9629385

mark poulson · Post by **mark poulson** » Thu Mar 19, 2009 5:44 am

I have an X15 on the bow, and a 997 on the console, and have the same problem.
I replaced the transducer on the TM, and it went away for a while, but now it's back.
Bottom loss, and interference, and loss of detail. The new transducer is only three months old, and has never been rubbed in the dirt on the lake.
I've been told that the bottom of the transducer needs to be smooth, and that accumulated scratches, from bottom/cover encounters over time scratches the bottom face and causes degradation of the signal.
I'm going to try and polish the bottom today, and check it out to see if that works.