Lund Wiring Help

So I own a 2004 Lund Fisherman 1700 and it’s starting to show its age, nevertheless a good boat but it’s giving me some problems recently.

I just bought a brand new battery for the trolling motor. The last one lasted about a year and after being on the charger for over 24 hours last week I got 20 minutes out of it on a perfectly calm day before it died (it’s a 12v minn kota power drive). There’s always been this cable running from the back of the boat to the trolling motor and I’ve always hooked it up. Me and my dad could never figure out what it went to and I wondering if whatever it is is the reason for such a short time of use.

Does anyone with this model or similar have the same thing? The previous owner did some of his own work in here so I’m not sure what’s factory and what isn’t.

I have a boat something like yours…. Only my on board charger and the trolling motor are wired to the trolling motor only battery. I have a 24 volt system but it shouldn’t change a thing.

Can you send a pic of the mystery cable and how it connects to the TM?

Might have used the TM battery to run something in the back of the boat.

Wonder if it was used to pull power from your starting battery in addition to your wire going to your trolling motor battery? Did the mystery wire going from TM to back of boat go near your starting battery?

I have no idea where the cable goes to. It runs off the TM battery to somewhere else in the boat but doesn’t lead to where the battery is in the back.

Brenden Marto wrote:

Me and my dad could never figure out what it went to and I wondering if whatever it is is the reason for such a short time of use.

Brenden Marto wrote:

I have no idea where the cable goes to. It runs off the TM battery to somewhere else in the boat but doesn’t lead to where the battery is in the back.

If it were my boat, I do whatever it takes to trace that cable and find out.

Is it one cable/wire or two?
What colors and gauge.
Pictures might help too.

Let’s apply a little basic troubleshooting here.

!. Disconnect the Magical Mystery Cable.
2. Try everything electrical in the boat to see what isn’t working. If you find accessories, lights, depth finder, etc doesn’t work, hook up the Magical Mystery Wire again to verify that’s what was powering it.

Next if you don’t find anything that the Magical Mystery Cable appears to power, things get a little more advanced. We need to see if you have some kind of dead short that is slowly draining your battery.

Generally, I’ve seen a lot of add-on wires on the TM battery because people are afraid of running the starting battery dead with constant use of the depth finder, GPS, etc. Also, the load placed on the starter battery when starting the engine wigs out some sonar units, so FWiW that’s a common one I see added on to the TM battery.

Another one I’ve seen is owners putting on a 2 wire harness that runs to a plug somewhere tucked away on the boat. Then they have a battery charger/maintainer with the matching plug so they can easily connect a battery charger without messing with alligator clamps, opening hatch covers, etc. Obviously, there would be wires to the + and – terminal for this to be the case.

Grouse

It may go back to a plug-in for a transom mount trolling motor but there should be two wires. Worth checking…..