Trolling motor help

The bottom of my trolling motor had a spot on it the size of a quarter where the paint was gone and it was very oxidized. In addition, any place the paint was scratched was rusting. I took this in and it was diagnosed with an electrolysis problem inside the motor and the entire motor at the bottom of the shaft was changed out under warranty. When I got the trolling motor back from the shop, it had 2 scratches in the paint of the brand new motor and after one trip on the water these scratches are showing signs of rust.

Has anyone ever experienced this? Do I still have a problem? Any chance my transducer on the bottom of the TM is causing this?

Any help is greatly appreciated….

I just sand mine, paint it black,and clear coat it.is yours a motor guide?

you might a ground problem. Don't hold me to that but I bet someone comes along that does have a answer for you. post your brand of motor and electronics

Trolling motor is a Motorguide Tour Series 24v and is 3.5 years old. It runs off 2 dedicated blue top batteries. I run two humminbird graphs an 1198 and 1158 and they run off my cranking battery. My front transducer cable runs down the outside of my TM shaft and is held pretty tight to the motor housing of the trolling motor.

Thanks for the responses...

If you are having a major electrolysis problem; go back to the big motor and take a look at things back there as the white power will be collecting in spots back there also. The block that is designed to collect this will be in bad shape. There will be some discoloring going on with your prop. and etc.. This pretty much tells you if there is a bad ground some where that needs to be fixed. If you don't see any thing unusual going on with the big motor, as the electrolysis will strike the two objects that hang down the farthermost in the water; then it will be just within the trolling motor. Look at another motor of a friend to compare yours to his so you can notice any major differences in the collection of the white powder on different parts of the motor, like the jack plate and etc..

I have seen motors do this because of several things:
- The plug for the trolling motor is not of the best quality.
- The plug wiring connections are not snug and as tight as possible.
- Happens more frequently with motors that are wired direct with no plug in.
- Happens most often when you do not unplug your trolling motor when charging the batteries.

I don't see any white powder anywhere at the big motor other than the 3 plates that are designed for it. My TM is direct wired as I had a problem with a plug catching fire in the past. I could trip the breaker before charging my batteries if that would help?

That will help. Unless you have a power cut off switch which will solve all problems of charging. When you put the batteries on charge that current runs through everything until it finds a stopping point at a plug or switch. Many stitches have been burned out on trolling motors because they were wired direct.

Two things I suggest you do:
- Install a plug in for the TM.
- Install a Perko Switch in the back of the boat.

It is important to have this done by a mechanic that knows exactly what he is doing. If not the problem may get even worse if grounding is not done properly.

Donald, could you give me a call at your convenience? 972-741-7353

got any pics of the TM in question?