Electrical Interference from DT115 on Lowrance DI?

[akareddog95]

I have a 1984 DT115 and I can't solve my an electrical interference problem on my fish finder. I have a three year old Lowrance Elite 5 Chirp fish finder. The problem only appears on 800 Khz Down Image. I have straight lines running straight up and down on the screen. I've tried ferrite choke and running the fish fisher on an independent battery. Lowrance customer service sucks.

I mostly trolling with my DT115 and only have this problem when I running the big motor. Has anyone else ever had this problem? I want to up grade to Humminbird Solix Mega, but I'm worried about more interferance problems. I heard someone once say it might be the spark plugs, can that be an issue? I believe I'm running Bosch plugs. Thanks Shane

[Solarman]

All interference I have ever experienced, has always been ground related on my Cat. I finally added new ground wires to items in my cat that didn't have ground straps, and tied both battery grounds together. Afterwards didn't have problems with bad static on radios and I'd say my garman screen even looked clearer (but not sure it was really affected).

I would check all items (metal) mounted throughout your boat, if there are any signs of interference. And if any ground connections are corroded, clean then reconnect. You might even check what your fish finder is grounded to? If grounded to the negative battery bar under dash, then make sure all connections are good/clean. If tied to some other wire(s) under dash, might move directly to the negative battery bar.

Good luck, post back when able.