kjfishman Posted May 6, 2015 Posted May 6, 2015 A friend of mine replaced the batteries in his Lowe Tahiti Deck boat. It is a 24 volt system after replacing the batteries the trolling motor was dead. We checked the batteries and fuses all were good. We suspected the the batteries weren't connected properly and and switched the ground leads on the battery. The motor worked briefly acting like it was a near dead battery but that wasn't the case. There are only 2 wires going to the trolling motor from the back of the boat. The connector that the the cable going to the front has red/blue tracer, black blue tracer, Red and black on the battery side I thought maybe the black wires were tied together at the connector but when I ohmed them out I only read a short one way. So my guess here must be an isolation circuit in the connecter and that has failed so no 24 volts to the motor. We reconnected the batteries like they were in a photo the owner took before disconnecting them. Any thoughts or information would be appreciated. Quote
Super User Wayne P. Posted May 6, 2015 Super User Posted May 6, 2015 What brand and model trolling motor? You stated two wires and listed four wires. What "connector"? How many batteries are on the boat? Quote
kjfishman Posted May 6, 2015 Author Posted May 6, 2015 The male connector in the battery area has 4 wires 1. red with blue trace 2. Black with blue trace 3. red 4. black that run to the batteries . Only two wires on the female side that runs up to the bow. The trolling motor is a Minn Kota 24 volt and runs off 2 wires. We never saw the 24 volts at the connector at the bow. We saw 12 volts on both batteries but did not see 24 volts across both when it we wired like the photo taken before the batteries were replaced . Didn't have a camera with me so no photos to post. Quote
Super User Wayne P. Posted May 6, 2015 Super User Posted May 6, 2015 The power to the trolling motor should be a red and black wire ONLY. Those connect to the red and black trolling motor power cord conductors. To get 24V there has to be a jumper wire between the positive post on one battery to the negative post on the other battery. Then the black wire is connected to the vacant Negative post and the red wire is connected to the vacant Postive post. That is a series connection that adds 12V + 12V to get 24V. If you do not have 24V accessories at the bow, any other wires should ONLY be connected to ONE of those batteries. Not even that if the boat is wired properly/safely. Does the boat have an outboard and bilge pump, lights, etc???? What are those connected to? Was a cheap install done and you only have two batteries on board that share engine starting, accessories and the trolling motor? Quote
kjfishman Posted May 6, 2015 Author Posted May 6, 2015 The trolling motor batteries are stand alone and nothing else runs off them. The mystery to me isthe connector that has 4 wires as described above going to the batteries and only 2 wires output that go to the trolling motor. Not just a simple jumper to put them in series. The boat is stored a distance away so will probably have to back and take the batteries out to get at the connector described above. Looked online and haven't any similar setup. Didn't see ant breakers in the battery compartment either. Replacing the original batteries that lasted 9 years started the problem. The power to the trolling motor should be a red and black wire ONLY. Those connect to the red and black trolling motor power cord conductors. To get 24V there has to be a jumper wire between the positive post on one battery to the negative post on the other battery. Then the black wire is connected to the vacant Negative post and the red wire is connected to the vacant Postive post. That is a series connection that adds 12V + 12V to get 24V. If you do not have 24V accessories at the bow, any other wires should ONLY be connected to ONE of those batteries. Not even that if the boat is wired properly/safely. Does the boat have an outboard and bilge pump, lights, etc???? What are those connected to? Was a cheap install done and you only have two batteries on board that share engine starting, accessories and the trolling motor? Quote
GPtimes2 Posted May 8, 2015 Posted May 8, 2015 I have the 2003 Tahiti Deck boat and mine only has 2 wires (plus the jumper) for the trolling motor that run up the left side of the boat. The policy when I bought mine was, only the trolling motor ran off those batteries. Everything else ran off the starting battery. Maybe they (or someone) added an on board battery charger. You will need to trace all the wires to know for sure what is happening. Lowe put round plastic access covers in the floor and in the sidewalls under the seats. When you go back, take a cordless screw driver and Phillips bit and find where those wires go. You mentioned series before, so I think you know how to wire it to get 24v up front and 12v somewhere else (if that is the case). I think this will turn into an easy fix for you. Hope this helps. Quote
Super User Scott F Posted May 8, 2015 Super User Posted May 8, 2015 Are you sure that the 4 wires present did not at one time hook up to a 2 bank battery charger? In my boat, I use 2 of the wires that run the motor to connect to my battery charger and ran 2 extra wires to complete the charger connections. Quote
Super User retiredbosn Posted May 9, 2015 Super User Posted May 9, 2015 My boat has a 36 volt tm, the batteries aren't even in the same compartment, rather they all run to a junction box located in the aft compartment where the battery chargers, cranking battery etc are located. It is here where the batteries go from stand alone to series, then two wires from junction box to the trolling motor. Each battery has four wires, 2 go to the junction and 2 go to the charger. Your boat may have a similar set up, if so just trace the wires back to their source. Good luck Quote
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