I am finally getting around to an old problem I have just been living with -
interference on depthfinder from trolling motor...

H'bird 787, MinnKota universal sonar II, seperate batteries

fine at speed 1 or wide open, but at 2-3 or so, get blue "grass" coming
up off the bottom that no amount of filter or lack of sens. will get rid of.

I remember something about connecting the ground on my starting battery
(that the df is hooked to) with the trolling batteries??? This ring a bell
with anyone? Anyhow, I'm a little confused on the tm battery end of it
as to where to hook it. I'm running 24V tm, and the boat is wired with
each batt. hooked 12V, then it is jumpered in the panel up in the bow...
Clear as mud?