sounder and electric motor interferance

[ANYFISH]

gday all
i have just bought a lowrance x87 sounder and it works bloody beautifully until i start me electric motor. the screen just gets all cluttery until i turn the electric off. if anybody knows the cause or how to fix the problem, any onfo will be verry handy.

thanks anyfish

[steelcat41]

If the tranducer or the display unit are situated too close to the motor you could get interferance. This is caused by the magnetic field created by the motor. You may like to try different positions for your fish finder. Also many electric motors (not 100% sure if this will apply to electric outboards) create interferance for other electrical and electronic equipment when their brushes wear out.
When the brushes start to wear out it causes arching and sparking, this might not be noticable to you but sensitive equipment will pick it up.Like I said I do not know if this will apply to your motor, I dont have an electric but I am sure somebody can shed some light onto that for you. I am curious as to whether they have brushes or not, and if so do they require servicing?
I have had to replace the brushes on my angle grinder before and its only 3 years old.

If you are using the same battery for both you may get interferance also.

Darryn

[peterbo3]

Anyfish.
Are you running the sounder & elec motor from the same deep cycle? If so, try running the sounder from a stand alone battery.Are any of your electrics earthed to your hull accidently (alloy only)?
Another cause of such interference is running the transducer cable/sounder power cable close to/parallel to your elec motor power cable.If this does not apply to your setup, it is possible to obtain inline suppressors/filters to screen out interference from other electric devices.
As stated above, if your elec is old it may run OK but produce a large electromagnetic field. Is your transducer close to your elec? If so, try relocating your elec & see what happens. Just undo the clamps & hold in the water away from your transducer & turn it on.

[ANYFISH]

thanks. the electric and the sounder are the only things on the battery so maybee i'll have to get another battery. does anybody know if i can fit a suppressor/filter to the sounder wires and fix the problem without needing to buy another battery? the motor is a fairly new minnkota 55lb and i don't know if it works off brushes or not.
cheers anyfish

[jaybee]

mite also pay to send lowrance au a email they are fairly quick with replies, even the 1800 number they are fairly helpful ppl
cheers
joe.

[peterbo3]

Anyfish,
I am betting that the problem relates to running the sounder & elec motor off the one battery. ;) ;) ;) ;) To check this,use your car battery to run the sounder & see what happens. If this does not fix the problem, check all your wiring & position of elec motor as per above post. Fitting filter/suppressor should be your last option.

[team_mongo]

Anyfish,

had exactly the same problem with a x85 and MinKota Autopilot 44. The sounder goes to shiet when the motor is on.

Does your motor have maximizer? Tthe electric motor has a high frequency cycling, causing a lot of electrical interference on the main bus line.

Tried a choke on the main line but it wasnt good enuf. So ended up having two batteries - 1 for the sounder and one for the electric. The one for sounder was a little motor bike battery.

cheers
George

[sharkbait]

On another note Peter, I have rewired all my electrical with trip fuses as per your instructions at the m+g. Thanks very much.
Kris.

[ANYFISH]

thanks heaps
looks like you fellas really know your stuff. i got another battery and tried it and the sounder worked perfectly.the lowrance is a quality unit and i thought the problem would be easily fixed with the right advice.