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oldtimer57.
In my 95 Eyra, I have a 24/36 volt system. I had 2 24/36v Motorguide Beasts on it and just switched to a Minn-Kota Maxxum 101 36v. I obviously have a grounding problem because my anodes, jackplate, prop and whatever exposed metal surface beneath the water turns chalky. I posted this before and I had never resolved the issue. Im a visual guy and need an idiot proof pic to help a brutha out. I am only running 3 batteries and Im told that the “routing” of the batteries is such that the cranking battery is acting as ground and the motor is grounding out the basses as I drive by. Being a guy who fishes 20 from the boat “always” not a good thing. HEEEEEELLLLLLLLPPPPPPPPP!!!!!!! Any pics would be greatly appreciated!!!!!! Eric
This seems like a hard one to get wrong. On your cranking battery, the – post goes to the main engine ground, and to the main ground for your electrical system. The + goes to the main engine positive (red cable) as well as the red cable going to the dash. For the other two batteries and the two TM wires, you do this: take the + on the cranking battery and wire to the – post on battery 2. Take the + post on battery 2 and wire to the – post on battery 3. take the + post on battery 3 and wire to + on the 36 v TM. Take the – post on battery 1 and wire to the – (black) on the TM. This gives everything a common ground reference at the negative post on battery 1. I have seen them hooked up the opposite way, which will work but which also leads to a ground differential. The wrong way is to take the – on the cranking batterh to + on battery 2, – on battery 2 to + on battery 3, and then use – on battery 3 as the TM ground, and + on battery 1 as the +36 volt source for the TM. Done that way you can have a potential between the two grounds and that leads to the electrolysis issue you mentioned. Hope that helps..2008 Pantera Classic2014 Mercury Pro XS 200
We really try to not give word advice on this one, as there are three systems in a BCB, and they do easily get this one wrong frequently. A 95 Eyra has four wires labeled 1 & 2, with one set going to the Cranking battery with the ground on the #1 usually, then positive to one of the Trolling batteries. There will then be a ground strap between those two lines which turns 12 volts into 24 volts. That strap we suggest a breaker on. The other will be #2 negative and positive only going to the one battery. The 36 volts is made in the tolling motor plug at the bow. The receptacle will have 24 volts when you hook the two up, and would have 12 volts on the opposing two prongs slots. If the engine gets electrolysis as some do on older rigs, then reverse the wires swapping the #1 and #2 leads to the opposite batteries. The ground plane should be the same as the troller and the crank batteries. That is that fuzzy which corrosion you will see after a few hours on the engine cathode (sacrificial anode) and trolling cathode plates, which are Zinc.
My current boat (Non-BCB, hope to change that one day soon) came from the factory so far beyond screwed up it took sunlight 6 months to get from screwed up to my boats wiring. It used 3 batteries, with a 12/24 volt option for the trolling motor. I generally ran it in 24v mode as most of my fishing is on a river system, but I would occasionally find that 24v was moving a bit faster than I wanted, and when I dropped back to 12v, I began to notice the same electrolysis problem. Turns out the ground in 12 v mode was not in common with the cranking battery ground. I took the 4 wires running to the front, two from each battery, and combined them into two pairs. I used one pair for +24, and the other pair for -24, and removed the 12v option. On the foot control, I took the 12v option and converted that to a “constant on” something my TM did not have. With a common ground for cranking and trolling, the electrolysis went away. And I even noticed better performance on electronics when using the TM.2008 Pantera Classic2014 Mercury Pro XS 200
Thanks for the info. Currently messing around with it. It appears to be right with everything I have seen. I am going to try some stuff. Thanks for the info guys. Ill let you know how I turn out. I am going to make it straight 36 and be done with it!
The main thing is to have the black TM wire and the black power wire to the engine and the black power wire from the dash tied to the _same_ electrical ground. Then you have zero voltage potential between any two things that might be stuck in the water (and dont forget the bilge water so everything needs a common ground to get the ground reference voltage to 0.0. Ive been tracking a computer room problem for quite a while, and last week took the main breaker panel cover off in the computer room and started measuring voltages and found some odd stuff going on. Voltage potential between the neutral (wiring ground) and earth ground for starters. Got the campus people over and started tracing wire where it comes into the building. We run 3-phase power which means 4 wires. 3 hot plus the electrical neutral. And then a 5th earth ground. Whomever installed this big transformer forgot to tie neutral to earth ground at that point, which leaves a floating neutral. Not good for GFI outlets and such as they wont work right. Tying all “grounds” together solved this, and will stop your electrolysis cold.2008 Pantera Classic2014 Mercury Pro XS 200
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