pretty blue lines

[beagle man]

got a question any ideas why when I use the auto piolit on the terrova it put noise on the 777 HB? the 777 is not on the same battery as the trolling motor,and the noise is a lot of blue. built in transducer on the trolling motor,

[Barnacle Bill]

Check this out: http://www.humminbird.com/support/FAQ.aspx?faqid=52
Especially the part about running a ground wire from the TM to the same battery as the 777 is on.

[beagle man]

Thanks IBNFSHN will give it a try

[oldwun]

You have aground loop it sounds like. Actually everything will work better if you have 1 common ground point.