trolling motor interference on Lowrance LSS-1 transom mounted transducer ?

Thought my Lowrance StructureScan install went without a hitch - plug and play. I couldn't be so lucky. whenever I turn on my trolling motor, the structurescan screen turns pretty much all white from interference on any spped except the highest. At the highest speed you can see interference "waves", but you can read the screen. Thing is, my transducer is mounted on the transom ?
I have a bow mounted Motorguide W75 wireless t.m. It uses 8 gauge wires run to it's own set of batteries.All of the wiring for the t.m. is on the opposite side of the boat of the Lowrance.
The Lowrance 85/200mhz transducer works - no interference. Structure Scan is useless with the trolling motor. All of the Lowrance gear runs to the cranking battery - ALL of the wiring is on the opposite side of the boat - don;t even share a fuse box as they all have inline fuses.
The only thing I cam across that was a remote possibility was it was mentioned you could ground the negative terminal of the cranking battery to a negative on a t.m battery. Tried it - same result.
the interference is just as bad at 455 as 800.
I has just hooked all of this up and took out my old sonar and put a 2nd HDS in the bow. Have not hooked up the 85/200 transducer to it yet as I am still trying to figure out the best way to do it - a Motorguide wireless does not easily take a transducer as there is no where to run the wire. Figured no big deal, i would have the structure scan transducer - even tho it was in the stern.
Nope. Went out for an all nighter - ended up messing with this most of the night. Just me, but I like to know the depth etc when i am in the bow drifting a shoreline, especially at winter pool. Obviously couldn't do it because of the interference.
ANY help is appreciated. I amk guessing it has to do with the pulse modulation - but at no point do any of the wires even come close to one another.......has to be transmitting the interference thru the air ?
and i was so happy withy my new electronics.....

What part of Tn you located?

Where is your LSS1 located? Do you have a tin boat and if so, is the TM isolated from the hull?

I'm sure there is a fix somewhere. I'll be interested in how this gets resolved.

Doesn't sound like the transducer has anything to do with the problem. I would say you have a grounding problem. Make sure your ground wires are tight. Are you using the same battery for your trollig motor as you are for your electronics? Do you have a filter in the power line to your display? I would use separate batteries for my trolling motor and electronics.

Here is some reading for you. http://www.crappie.com/crappie/fishi...erference.html

I am in Tullahoma.
Is a fiberglass hull.
Trolling motor is on it;s own set of batteries, on the other side of the boat.
Since posting this I cam across what seems like some really good info HERE
Supposed to have rain for the next few days......wondering - could I just stick the transducer in a bucket of water or does it have to go to the lake ? Be nice if i could work on it at home until the screen doesn't go totally blank, then go test it on the water....
In the link I posted, he said do it as a last resort, but i may try it 1st just to see if it works - use a small lawn mower battery and put it right by the LSS-1.
The LSS-1 is mounted under driver's area. Actually, I guess I could try moving it to the back of the boat by the cranking battery - although i am guessing the transducer is where the interference comes from, not the module.....will try it and see

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Originally Posted by donberry

I am in Tullahoma.
Is a fiberglass hull.
Trolling motor is on it;s own set of batteries, on the other side of the boat.
Since posting this I cam across what seems like some really good info HERE
Supposed to have rain for the next few days......wondering - could I just stick the transducer in a bucket of water or does it have to go to the lake ? Be nice if i could work on it at home until the screen doesn't go totally blank, then go test it on the water....
In the link I posted, he said do it as a last resort, but i may try it 1st just to see if it works - use a small lawn mower battery and put it right by the LSS-1.
The LSS-1 is mounted under driver's area. Actually, I guess I could try moving it to the back of the boat by the cranking battery - although i am guessing the transducer is where the interference comes from, not the module.....will try it and see

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As it is probably a stray voltage problem, you could probably do all the testing you want with it out of the water completely. Transducer and all.

Read thru the info Barnacle Bill posted.

Quote:

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Originally Posted by FAADAN

As it is probably a stray voltage problem, you could probably do all the testing you want with it out of the water completely. Transducer and all.

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yep.