Trolling motor / AM radio interference

[92python]

One thing I want to fix before the open water season is to get rid of the annoying effect my trolling motor has on my boat stereo when listening to the Twins games on AM radio. The stereo and trolling motors are plugged into different batteries but when I am listening to the game and I turn on either trolling motor I get a sound that starts with a certain pitch that gets higher then lower while the trolling motor is on and you can't really listen to the radio.

Any ideas? Will some sort of filter between the stereo and it's power source or stereo and the speakers work?

[LwnmwnMan2]

I'm going to be of no help to you at all.

I posted this exact same thing last summer and was told there's no fix.

I know there's a fix, because I'd just bought a new boat last summer and it's the one doing it.

My old boat, you could listen to anything, on any station, and there was no whine.

Now that you've got me thinking about it, I think I'll head to Radio Shack tomorrow.

Gotta put that on the to-do list I guess.

[katoguy]

There is no fix if your motor has a pulse-width modulation unit (aka Minn Kota Maximizer or Motor Guide Dura Amp) other than distance. Cheaper models of either brand that are set 5 or 4 speed units instead of variable speed motors should not interfere.

[92python]

Should have skimped on the trolling motors. What a bummer to have a Vector and a Power Drive Autopilot!!! Maybe I should try a lead blanket for my stereo. I am going to try a walkman and a portable radio and see what happens with the trolling motors on.

[RobertELee]

Google crutchfield and do a search for noise filters. They have an American International S15A filter that may work for you. If you are unsure give them a call and they should be able to hook you up. They are only $12.99.