Strange trolling motor issue

[N Florida Mike]

I have a 4 year old Minn kota trolling motor. It runs fine when it's out of the water. As soon as it touches the water, it quits. I have never had this problem in owning various units for 35 years or so.

The battery is new and well charged so it isn't that.

I also just put new clamps on to try and solve the problem, but it wasn't that either.

What do y'all think ?

[Brew City Bass]

Pull the prop off, check the seals. My best guess is water intrusion causing a short or something of the sorts.

[Todd2]

I've heard of outboards starting up and running fine with rabbit ears but dying when put under load (water). I guess it could be something similar but I'd guess electrical like Brew said.

[Scott F]

Did you take the prop off and check the drive pin? They can break and leave enough of a rough edge to turn the prop with no load but slip when there is any resistance. 

[N Florida Mike]

Not yet. I had thought it just needed new clamps and was getting a poor connection. 

I'll check that and for water intrusion like brew said.

It seems to have full power out of the water so it seems like it would in the water too. But it won't turn it even slightly.

 

 

[Tim Kelly]

Can you hear the motor running when it's in the water? If the motor's running, but the prop's not turning then it's probably the pin. If the motor doesn't run in the water, try holding the prop out of the water and starting it, see if the motor's really weak and it will turn the prop in air, but not in water. That might be the motor or might be the battery, or a connection.

[Slade House]

Did you check the electrical breaker on the positive cable.  This happened to me.  

[N Florida Mike]

9 hours ago, Slade House said:

Did you check the electrical breaker on the positive cable.  This happened to me.  

No. Where is it ?

On 7/20/2018 at 10:29 AM, Tim Kelly said:

Can you hear the motor running when it's in the water? If the motor's running, but the prop's not turning then it's probably the pin. If the motor doesn't run in the water, try holding the prop out of the water and starting it, see if the motor's really weak and it will turn the prop in air, but not in water. That might be the motor or might be the battery, or a connection.

The motor does not run in the water. Nothing happens. When I pull it out of the water with the handle on, there is a pause , then it comes on. It also works if I pull it out , then turn it on. It appears to be as strong as ever. Connections and battery are good.

If I have it running and put it into the water, it immediately shuts off. 

[Tim Kelly]

It's definitely whether it's in the water or not and not the angle it's at? if you drop it down when the boat's on the trailer, does it run? Just wondering whether there's a short when the motor is at a particular angle cause by worn wires. Would be quite odd for the water to stop it working, but as soon as it's out of the water it worked, as it would still be wet.

[N Florida Mike]

9 hours ago, Tim Kelly said:

It's definitely whether it's in the water or not and not the angle it's at? if you drop it down when the boat's on the trailer, does it run? Just wondering whether there's a short when the motor is at a particular angle cause by worn wires. Would be quite odd for the water to stop it working, but as soon as it's out of the water it worked, as it would still be wet.

Good point. I haven't had it on a trailer because the boats in the lake behind my house. I'll try clamping it to a sawhorse and see if it's the angle, but it literally works fine until it hits the water so that would be amazing odds to have a short in the exact angle that it makes when it hits the water.

I haven't had time to do anything else recommended yet but I'm getting closer !

 

[N Florida Mike]

Took the prop off and found a wad of line all around it. Got that all off, put prop back on, thinking that's surely whats wrong. Well, it still doesnt work. When the motor is in full tilt it works most of the time. When it is lowered to normal running position, it usually wont work atall. If I tap on the top of the box it spins a little. So somethings wrong in there.

The pin was fine, by the way.

[Slade House]

On 7/21/2018 at 4:12 PM, N Florida Mike said:

No. Where is it ?

The motor does not run in the water. Nothing happens. When I pull it out of the water with the handle on, there is a pause , then it comes on. It also works if I pull it out , then turn it on. It appears to be as strong as ever. Connections and battery are good.

If I have it running and put it into the water, it immediately shuts off. 

Mike,  if you don't have one of these on your positive cable between your trolling motor and the battery whats happening to you will happen.  Think of it like a 50 amp breaker you would find in your breaker box at home. What happens if you plug in a hair dryer and the breaker is switched to off?  The hair dryer won't turn on right?   This is what is happening on your trolling motor.     I mistakingly took mine off the  positive line on my MGuide XI5 . Even though i installed a 30 amp fuse on the postive line using an automotive fuse thing it did the exact same thing yours is doing with the exact same symptoms.     These cost 8.99 at cabellas, go buy one now and i bet you it will work.  

[N Florida Mike]

Huh. Does it fit right under the housing ?