need trolling motor help please

[floydp680]

i have a 97 fisher fs18 fish and ski made by tracker. it comes stock with a motorguide 748v. there is a plug from the pedal to a relay, then two positive wires and two negative wires that go to the two batteries. its a 48 volt trolling motor, but the plug is 12 volts, and it only seems to drain one battery. when i charge them one is always still charged. the motor is very weak and cant keep up with moving water or wind. the wires are paired so that one set goes to one battery and the other goes to the other. theres one set that are orange (positive) and black (negative), and the other is red and black. any way i connect them its always the same. was the plug changed before i bought the boat and wrong? How can I get 48 volts of power to have control of my boat?

 

[Silvertip]

Re: need trolling motor help please

You don't have a 48V motor you have a 24V motor. Two twelve volt batteries in series provides 24V. Two batteries in parallel still provide only 12V but double the run time. You are not getting the 24V connection right. I need to ask some questions. Does the receptacle on the boat have two, three, or four terminals in it? Does the boat have a switch near the receptacle that says 12V/24V/Charge or something like that? Does the trolling motor foot pedal have a 12/24V switch on it? Answer those three questions and I'll get back to you.

 

[floydp680]

Re: need trolling motor help please

You don't have a 48V motor you have a 24V motor. Two twelve volt batteries in series provides 24V. Two batteries in parallel still provide only 12V but double the run time. You are not getting the 24V connection right. I need to ask some questions. Does the receptacle on the boat have two, three, or four terminals in it? Does the boat have a switch near the receptacle that says 12V/24V/Charge or something like that? Does the trolling motor foot pedal have a 12/24V switch on it? Answer those three questions and I'll get back to you.

 

[floydp680]

Re: need trolling motor help please

that was a typo, i do have a 24 volt motor. the receptacle has 4 terminals. there is no switch on the boat or pedal. the pedal has a toggle that can be switched between constant on, mom, or hbp. with mom it just goes when you push the button. on the backside of the female plug (in the boat) there are the 2 positive cables and the 2 negative cables that go back to the batteries. i think that the male plug is wrong because it only specifies 12v but plugs into a receptacle that says 12/24. i ordered a 24v male plug today. if that is actually the problem, after that how do i wire in series to get 24v power.

 

[Silvertip]

Re: need trolling motor help please

I take it you just bought this boat? Someone has mucked with the wiring. There are several ways to wire two batteries to get 24V. One is a two wire system and the series connections are made at the batteries. In that system there are only two wires going up front. 24V and ground. You do not have that system. A four wire system is wired as your boat is. Here is where it gets complicated. Just because there are four wires doesn't mean you have 24V. That doesn't happen unless the receptacle has a special "jumper" on it that makes the series connection. The two pin plug you have will work just fine as long as the +24 and ground pins match the pins in the receptacle that have 24V and ground on them. Without that jumper all you have is two 12V circuits in parallel. That same system is used to provide both 12V AND 24V to motors that can run on either 12 OR 24V. There is normally a 12/24 switch panel on the boat though. Your system with that relay makes me think the relay is supposed to do the 12/24 switching when you step on the go pedal and its not doing it's job. It's therefore possible the relay is bad. I will look through my schematics and provide one that is far simpler, you can eliminate the relay, and you won't need a new plug. But check the relay first. I doubt the plug is the problem UNLESS the cable leading to the foot pedal has more than two wires. Then the four prong plug makes sense. But if the cable only has two wires in it, a four prong plug would need to have the jumper in it similar to what I mentioned earlier. This appears to be a strange wiring scheme.

 

[floydp680]

Re: need trolling motor help please

it is the original wiring, trolling motor, and everything. i have had the same boat in the past (exactly the same) wiring and all. this is the way this boat came when new and i am thinking that maybe the plug has been changed to 12v only or it just came that way when new. in any case i will replace with the 24v plug. my plug now does have 4 pins though and the female end has 4 holes. behind the female plug there is a connection where the 4 battery wires come off of and go to the back. it just looks like a block that they connect to, doesn't look too complex really. btw thanks for helping me think this out, i dont know much about electrical, i am explaining everything as best i can.

 

[Silvertip]

Re: need trolling motor help please

Here is a diagram of how I think your system should be wired. Note the green wire between the two batteries. That wire is what makes for 24V at the receptacle. There are several ways to make that connection however so you need to determine what that relay box is doing. The relay box may be making that connection. In some cases there is a jumper wire on the back of the receptacle. In others there is a switch panel next to the receptacle. With this wiring you would not need that relay box. Check the cable between the trolling motor plug and the foot control and let me know how many wires are in that cable. If there are only two wires in the foot control cable the only thing you would need to ensure is that the two pins on the trolling motor plug match the two pins that provide 24V to the receptacle. The relay could then be eliminated. The two 12V pins in the receptacle would not be used. I really doubt the plug on the trolling motor has anything to do with this problem.

 

[floydp680]

Re: need trolling motor help please

there are 4 pins in the plug, there is no switch so i used the small print at the bottom of the diagram for reference because that is how my boat is. i followed your diagram and used 80 amp inline fuses and the original plug for the trolling motor. when i plugged it in it immediately popped the 80 amp fuse that goes to battery one in your diagram. what next?

 

[floydp680]

Re: need trolling motor help please

i had 40 amp fuses left over so i switched my wires and made my battery 1 battery 2 and my battery 2 battery 1. i then plugged it in and immediately popped battery 1 fuse again. i did seem for a minute as if i had 24 volts of power to the trolling motor even with the popped fuse. i am so lost. im going fishing this weekend. please help.

 

[floydp680]

Re: need trolling motor help please

alright, i only used one set of wires and then connected the 2 batteries and it works.