Thread: trolling motor issue

was wondering if you should run the trolling off the same battery as your fish finder?

the reason i ask is i just bought a new bow mount trolling and have a old Lowrance fish finder and i notice it messes up the fish finder while running the trolling motor, it wont read the bottom or show fish only the depth.

thanks

From past experience and from those who are more knowledgeable than I am, it is best to run your trolling motor off of a separate battery. Some fishfinders pick up noise from the TM if they are hooked to the same battery.

Run it off your starting battery. They do not draw enough current to even consider. Also by doing it that way you can use it to tell if your charging system is work ok. If it has the capability of showing voltage.

good answers

forgot to mention that i have a 25hp pull start so i only have 1 battery for all.

i plane on buying a new finder in the near future so would that probably solve my issue, are new ones now days did away with that

Even if you plan on buying a new one, I would still run it on a separate battery. TM noise is gonna be there and it will "probably" affect your fish finder, even if in a small way. The other thing to consider is a spare battery is always a good thing. I ran my fish finder and trolling motor off the same battery for a long time with no "noticeable" problems but when I added a spare battery, I hooked the fish finder by itself to it. Thats when I noticed the difference, and I have needed a spare battery a couple of days when the wind was up. Just my 2 cents.

Originally Posted by TnT

Even if you plan on buying a new one, I would still run it on a separate battery. TM noise is gonna be there and it will "probably" affect your fish finder, even if in a small way. The other thing to consider is a spare battery is always a good thing. I ran mt fish finder and trolling motor off the same battery for a long time with no "noticeable" problems but when I added a spare battery, I hooked the fish finder by itself to it. Thats when I noticed the difference, and I have needed a spare battery a couple of days when the wind was up. Just my 2 cents.

Your 2 cents would be worth 100 bucks on a windy day.

thanks for your responses. point taken

If a 2nd battery is not an option, you can run a ground wire from your TM foot back to the negative terminal of your battery and that should clear up the noise. Just sand off a small spot on the skeg of the TM, put in a sheet metal screw, paint over and snake it back. Problem solved.

However, a small auxillary battery would be a better deal in the long run.

Wannabe...

Well put Wannabe!!!!!!!!!!!!!! That would be the best!

Originally Posted by Wannabe...

If a 2nd battery is not an option, you can run a ground wire from your TM foot back to the negative terminal of your battery and that should clear up the noise. Just sand off a small spot on the skeg of the TM, put in a sheet metal screw, paint over and snake it back. Problem solved.

However, a small auxillary battery would be a better deal in the long run.

Wannabe...

I don't understand why this fix works, but it does. Theoretically, you are introducing a ground loop to the TM, which, in theory, would only induce more noise and also create current loops thru the hull if it is a metal boat.