Trolling Motor wiring

Hi.

I have an older Lund pro v boat and am trying to decipher how the trolling motor was connected to the two battery system. It is a 12 volt system, so they would be wired in parallel, but there are extra wires and am not sure what they are for or whether in the right place anymore. The fuses for the wires are on the wire near the batteries. Also, there is a plug in at the back of the boat for charging, so am assuming some of the extra wires are for that. Lund says the boat is too old for them to help me and the user manual wiring diagram isn’t detailed enough.

Is there a way to unravel this? Are there a set # of wires I should be seeing?

Thanks!

The extra wires were likely for using a 12/24 Volt system that “jumps at the plug”

Use a multi-meter to determine what wires are what, and their voltage/polarity.

I had a ’98 Lund. It had 3 factory wires for the 12/24 volt combination plug, it also had factory wires for volt meters for each battery. Of course I had my own wires run from On Board Charger and ran my graphs off trolling motor batteries. I would use my multimeter measuring ohms to find out which wires went where I needed them (you will probably have to make some long test leads to reach both ends of the wires). Then when you think you have it wired how you want it, make sure you have correct voltage before connectiing trolling motor and accessories.

It will be a pain in the ass, but worth it it long run. mark wires so you will know next time.

Good Luck.

Thanks for the advice! I had forgotten about the voltage tester up front, which explains the extra red and black main wires. The only other wires are lighter gauge reds and blacks for each battery, which I’m assuming go back to the charger, but can use a tester to verify.

I wonder if I should also run my sonar off the trolling motor batteries? I’m getting a new Lowrance Elite FS to replace my 25 year old Lowrance X25 and even now the X25 resets when I run a spot light off the cig lighter plug, as I think the light is too much of a load given I only have one battery in the back?

Thanks.

Dave Dauksas wrote:

I wonder if I should also run my sonar off the trolling motor batteries? I’m getting a new Lowrance Elite FS to replace my 25 year old Lowrance X25 and even now the X25 resets when I run a spot light off the cig lighter plug, as I think the light is too much of a load given I only have one battery in the back?

Thanks.

I dont know if I would do that. Some people complain of interference when they do that. All my units are wired to the rear cranking batteries (2 in parallel).

I wish I had room for a 2nd cranking battery. I have the oil reservoir where it could possibly go, but until/unless I switch to a 4 stroke engine, I’m out of luck. Thanks