Sonar interference

[dvl2700]

I had a 14 gauge shielded marine wire running from my starting battery to a Blue Seas Fuse Box under the dash. When I updated and added a second sonar to the bow, I jumped my wire to 8 gauge, but they do not make a 8 or 10 gauge shielded marine wire. So I used a standard 8 gauge marine wire. Now I am getting a lot of interference when I have the motor above an idle speed.

If I separate the 8 gauge sonar wire by putting it on the post with the below photo, and have it separated from the engine which goes onto the battery screw post would that be enough to separate the two components (engine and sonars) so I don't get interference ?
IMG_3497.jpg
BTW, I know just enough about electronics to be dangerous.

Ran the old shielded wire out in the open and will test both this weekend. Hope I don't get too much voltage drop due to the smaller gauge. At least I will know what the issue is. THOUGHTS ?

dvl2700

[Bill Reynolds]

Watching.

[bobcoy]

What is the interference on? #8 wire should not change anything about interference. Make sure your motor is still grounded direct to battery with a large gauge wire. Smaller wire is more likely to show interference than a big one. Bob

[dvl2700]

Well this weekend was out and had the 14 gauge shielded wire run and hooked up. A lot less interference and screen noise when running with the old 14 gauge wire vs the 8 gauge (non shielded) wire. Did not fish or run the unit for a long time, but did not notice significant voltage drop when tested with a multi meter. Going to continue to use the 14 gauge shielded (twisted) wire.

[Avanti]

What is the shield grounded to ?
The interference reduction may have more to do with the twisted pair.

[Avanti]

You could try making a twisted pair using a drill and your 10 ga wires. There are youtube videos that show how to do it. Same way technicians at work used to make twisted pairs.