Why would I have???

[Chadster]

I pulled my trolling motor deep cycle batteries out of the boat the other day and purchased a couple replacements. I also have a 3rd battery that I use for starting the kicker, and running electronics. Then there is the 4th which is the starting battery for my main OB (not part of issue).

So, tonight I dropped in the 2 new Deep cycles, and swapped in a better battery for the 3rd. I went to hook everything back up and it went fine except for one wire...

I had a small gauge wire (16-18awg) running from the negative terminal of the 3rd battery (electronics) to the negative terminal of one of the Deep Cycles (trolling motor - 24 v battery config).

Why would I have run this wire? I have had it like this for 3 years. I don't usually just add wires for something to do... (could mean trouble...) I think I read somewhere that by making that connection, it serves as a common ground between the TM batteries and the electronics batteries, and in turn reduces or eliminates noise in the sonar.

Does this make sense? Why else would I have done this? Everything went to **** when I turned 40, including my memory...

Thanks!

[VernH]

Shouldn't hurt to tie the true battery grounds together. It would need to be the negitive terminal on the lower battery of the two wired in series for the 24v system. Do you have a battery gauge? Maybe that is uses the unknown wire.

In the past I've not hooked up all the wire come spring. Smoked a small wire running to the motor when the starter tried to find another ground path. Some wires, especialy black, drop outta sight and aren't easy to see when it's time to hook things back up.

Now I take a handful of tywraps with me and when I remove connections from the battery, I run the tywrap thru the ring connector and hold all the connections for that terminal post together. Makes for a easy re install in spring.

Good luck figuring out your situation.

Vern

[frwhlr38]

Very Good point always mark wires somehow with tye wraps or tape or gets stick on #s so you know when come spring where they go i have a notebook on both my boats and i always write it all down if i add anything to them and make my own wireing diagrams it does help:smokin:

[fxnrxn]

I recall running a similar ground on my brothers pro v after talking to Lowrance about interference from his minnkota troller. Safe bet that's why it was run in the first place. Mike

P.S. I take lots of photos of any new wiring and use photo editing software to tag them. I know its not always practical, but it has saved me much time and frustration in the past. I keep a copy of photos in the boat, and one in my boat toolbox in the garage.

[micropterus]

"There is nothing absolutely nothing half so much worth doing as simply
messing about in boats."

[Nimstug]

Chad,

Could it be an accessory ground wire like lights, pump or gauges?

This last summer I had to take out my starting battery and when I put it back minutes later I missed hooking up the accessory ground wire. Small and dark just like Vern noted.

I hope it's that simple for you.

Nimstug

[PRD1]

FXrnr, That is what it is, did the same thing on mine to eliminate any interference between TM and boat electronics.