Common grounding with Lowrance Ghost?

[Ranger519VS]

Is it a good idea to tie the grounds together between the house battery and the trolling motor battery negative? Will it cause a problem?

[MBDiagMan]

The boat riggers will be along to tell you what is normally done, but the only path where they cross is the Ghost and the gadgets. If I were designing that connection I would isolate the circuits, but someone else did and they may have decided to share a common ground.

[R2Tracker]

Being the Ghost will be run on either 24v or 36v, I would recommend against establishing a common ground with your 12v system.

[Ranger519VS]

Being the Ghost will be run on either 24v or 36v, I would recommend against establishing a common ground with your 12v system.

That would not be a factor as you set the Ghost for your system on initial installation. There is no switch to change it back and forth from 24v to 36v.

[R2Tracker]

The point was it will either be 24v or 36v, not 12v... as such, I personally would not establish a common ground between the trolling batteries and cranking battery.

[mean_dean]

Isn't the common ground a solution for interference issues between TM and electronics? With the brushless motor the claim is no interference from the TM on electronics so in theory no need for it.

[Ranger519VS]

Isn't the common ground a solution for interference issues between TM and electronics? With the brushless motor the claim is no interference from the TM on electronics so in theory no need for it.

Like I said I am getting little dots scattered all over the depth screen when running the Ghost on Max. It is not the same kind of interference I got on the screen when running a Minnkota. Used to get a solid black line when hit the minnkota and then the auto sensitivity would correct and clear up the screen.

[Ranger519VS]

This is a screen shot I took of the Carbon unit while running the Ghost on Max speed setting for those who doubt. The transducer is the Ghost HDI. Don't notice any interference on lower speed settings. Something else, I found if I set the sonar on m/h Chirp the interference dissapears.

Lowrance interference.JPG

Incidentally, I installed the common ground between starting and trolling motor batteries but it didn't make any difference in the interference