Uncommanded motor trim recently.

It's happened 3 times in the last few months, always on the trailer. Runs full up or down, eventually stops then returns to normal. Trim switches at the bow, throttle handle, blinker and on the motor. Not sure where to start troubleshooting

Mine did that once in the rain. I guess it dried out because it hasn't done it since. Had to be the one on the bow. If you have a switch to cut power to all accessories and it still does it I would bet on the throttle handle switch. Otherwise I would start with the one on the bow. It's probably more exposed to the elements than the rest.

The switch on the bow is simply connected parallel with the one on the throttle and has power to the center pin all the time, same as the throttle.

The control handle trim on some brands are known for this. Like Bob said.

The trim solenoid is only powered by the 12V from the trim switch. Nothing else affects it. Switches are cheap, I would just replace both of them. If it's dirty or flakey contacts in the switch causing it to happen intermittently, you can waste a lot of time monking with it.

Thanks to all who replied. Bob, just so I'm clear, which two would you replace? Bow and throttle?

I would replace both of them. They're cheap. Also, check the cable under the console for exposed wiring just to make sure you don't have a bare wire touching something. it will be a small blue/red/green ribbon cable.

Thank you again, I'll report back

By process of elimination I found the trim switch on the side of the motor to be faulty.

Every boat that I have owned has done it at one point in time. It was always the bow switch that was the culprit.

Thats why I installed a battery cutoff. When it's off, nothing recieves power, preventing anything from operating "on its own", especially while driving down the road. Talons don't draw power, etc, etc..