So I’ve ran into an issue I can’t figure out. So recently my trolling motor wiring (the wires from the head to foot pedal) got hung on a dock cleat and broke the head off. It seemed to only break a few wires. I ended up wiring them back together and checked out the lower unit. A brown wire on the lower unit was broken so I fixed it. (Sonar wire I’m guessing?). Now my issue runs into, the propellor acts like it wants to spin turning it on, but only spins a few rotations and quits. I verified with a multimeter that I was getting 12.41 volts down to the bushing before connecting it to thaw armature plates. Still got 12.41 volts. I have verified the bushings are touching the plates on the armature. After putting it under load I tested the wires again at the head and the volts drops and fluctuates from 1.40-2.10 volts until it quits spinning and drops to 0 volts. I figured it would be easier to ask here if you all had any other troubleshooting techniques before I spent $150 getting some guy to “diagnose” it. I could t find any other threads that helped me. Thanks. Also I can’t seem to find the serial number. Possible got taken off the foot pedal.
The small brown wire is ground that goes under one of the brush plate screws,it helps to eliminate interference. If this is a 24 v motor you should have 25-26 v at the brush plate,about 37-38 v on a 36 v motor. There are wires splices under the top cap on the head of the TM. Minn Kota uses spade connectors there,you may have pulled one of those loose. The splices will have heat shrink around them so you’ll need to remove that.
Yeah I mounted the brown wire back on the brush plate. I don’t use the built in sonar on the trolling motor itself. Do I even need that wire or can I just remove it? It is a 36v trolling motor. I only have it hooked up to 1 battery at the moment (I’m pretty sure they recommend like 2 or 3 for it) but it worked perfectly fine before I broke the head off so I know that isn’t the issue there. I checked those connectors at the head and pulled back the heat shrink and that’s where I was getting the 12.41 volts before connecting the bushings to the armature plates. I can send a video of what it’s doing if that helps anyone.
Why do you only have 1 battery connected to a 36 v trolling motor? 36v takes 3 12v batteries, not just one, You need 36v at plug for it to run properly, at least that's my understanding.
It ran perfectly fine before on 1 battery. I just wired it up to 2 batteries and I’m getting no change in the issue. I can get a 3rd but it won’t fix the issue. It will still give power and turn on 1 battery, however it won’t give off the top speed/thrust on 1 battery.
It is OK to test a motor with 12 volts if it is 24 or 36 volts. Your motor is stopping and voltage goes to zero because you have a loose connection somewhere or the battery you are using is bad. The wire you fixed would be the first place I would check. Bit the brown one, but the red or black wire you repaired. You need secure connections. do not twist together.
So I pulled all wires out, I thought I broke the red or black wire but it only broke the brown wire and the transducer wire. I checked both black and red wires for any cuts or damage but I didn’t find anything. I’m thinking I somehow blew the armature and it went bad. I’ll order a new one and try it.
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