Need help guys,i have a motorguide 52 12 volt. Works great at home and in a trash can full of water. But as soon as i drop it in at the lake nothing. Its not popping the breaker it just quits. I checked all connections and even opened the motor to see if water was getting in. Brushes look good just wont work at the lake. Im about ready to throw it over board.

I'd recheck the wiring. It sounds like a bad connection in the boat to me.

can you mount your garbage can to the front of the boat?

just kidding, /../ intermittent electrical problems are almost always a bad connection.

When it quits, try barely turning the prop with your hand and see if it will start working. If it works then, then the armature is wearing out or dirty.

I vote let it sleep with the fishys.

And yes sound like a bad wire.

Tried turning it by hand. Nothing. A buddy of mine said if i keep it up he will have a video that will make Bill Dance laugh.

I have the same problem, mine will work when I turn it by hand

Actually sounds like you might have some water in the lower unit at one time or still do. Could also be a loose connection. Start at the batteries and work your way up. Pay close attention to the plug and circuit breakers. My parents live in Kemp so I can come by to check it out sometime soon if you'd like.

Is your boat aluminum? Do you have a separate trolling and starting battery, or one (or a pair) that serve both purposes?
If so, try running a wire clamped simple pony clamp, or hose clamp, just something to make good contact) one bare end to the trolling motor shaft, the other bare end to the boat hull near the trolling motor. Then try running the "driveway" test again. Might be a short between the trolling motor internals to the housing, and the boat hull (which is grounded to the motor via the hull, and therefore back to the battery(ies) if it's aluminum). Try it with the wire hooked up, and loose, and see if there is a difference (jumper cables would be idea for this test so long as you can get them onto the trolling motor shaft).
Reason it would work in the driveway normally is there is no "circuit" (no water) between the hull, and the motor (assuming the trolling motor mount is somehow electrically isolated from the hull, which I don't know in your case, if it's mounted to a wood plate, or has a rubber sheath around the shaft at the mount, for example). In the water, the water itself completes a circiut, possibly grounding the motor's positive (basically bypassing enough current from the motor so it can't turn).
This is a hail-mary theory, but it's worth eliminating, if nothing else.
If your trolling motor is solidly grounded to the hull at all times then this won't change anything. (Most likely, if you know how to use a voltmeter, do a continuity check between the hull and shaft while out of the water and deployed, if you get continuity, then this post is irrelevant). Also if the boat is fiberglass, the resistance of the water betwen the TM and the main engine would likely be too much to cause this problem, which is why I was wondering if it's aluminum, which might only be a 2 or 3ft gap between shaft and hull. Again, this isn't likely at all, just grasping at straws.

You shouldn't be using the hull to ground anything. The less current you have running through it the better because of electrolysis.
I agree with the above guys in that you have a wiring problem with the boat. You should have wires directly to the battery, probably 6ga., for both 12V and GND. Start there and it will be a lot easier to troubleshoot. If it works in a barrel connected to a battery, that should tell you where to start looking. It doesn't take much corrosion to mess up a connection, especially on the ground side..

Bob, that was the point of the testing, if something is wrong and the current is flowing through the hull, that's a problem. Not likely, but possible, and so the "jumper to the hull" might allow a driveway test.

On an aluminum hull with a motor bolted to it, the hull is at battery ground as well (unless motor is on a wooden transom, then less so, but even then current can flow from the mounting bracket through the water outside the boat to the hull next to the transom).

So what I was discussing was basically if there is a short from positive to the TM shell, but the TM is well isolated from the hull (rubber mounting isolators or something similar), then out of water, it might continue working, but in water, the water completes the circuit back to ground and bypasses the higher resistance motor windings.

No matter what, it's clearly a wiring issue somewhere, it's just odd that it works in a water tank in the driveway, but not when the boat is actually in water, which leaves the only real difference being water between the hull and t-motor when in the lake, versus air between the hull and t-motor in the driveway. Jumping (in the driveway) betwen the trolling motor external shell, and the boat hull, is the only way I can conceive of to replicate/test that possibility (not leaving it that way after testing, just strictly for that test).

Its on a fiberglass skeeter.

There goes that theory, it was a stretch anyhow, just weird that it'll work in a bin of water, but not in the actual lake. No more creative ideas from me, it does sound like water is getting in, or a wiring problem, but the inability to reproduce the problem at home is odd. Good luck!

Fixed i hope