Stuck Trim in Up Position

[southstar]

Have a 175 4 stroke Mercury. Trim got stuck in up position while on the lake, had to be hauled in. Later discovered how to manually lower motor. However, in a few minutes the trim raised again and motor kept running then quit. Manually lowered again but in a few minutes it came back up. Had to disconnect wires to trim. Now I can lower the motor but have no trim control??? Its like the trim motor would run until the heat switch protecting the motor turned it off, until it cools off, then back on again??

 

[Chris1956]

Sometimes the thumb toggle switches for the trim get water in them and the water completes the up circuit.

See if you can blow it out, or replace the trim switch. Obviously you will want to test if first.

 

[southstar]

Sometimes the thumb toggle switches for the trim get water in them and the water completes the up circuit.

See if you can blow it out, or replace the trim switch. Obviously you will want to test if first.

Thanks Chris for your response. This is a 2012 Hurricane Deck boat, I keep it covered in a boat slip. The thumb trim switch is in the throttle/shift stick and of course one on the side of the motor. When I got the boat towed back, I removed the cowling and disconnected one set wires going to the switch on the motor. then when I turned the power back the trim motor started and it stays running even after 100% up. In a few moments the motor stops. I think a heat protected switch in the motor. It seems to cool down and then start again even though its up. I disconnected the other set of wires at the engine trim switch and manually lowered the motor. Obviously I can run the boat now w/o trim. I have no idea how to get to that trim switch in the throttle but I don't see how water could have gotten in there. If I leave the wires connected the trim motor will keep running and cycle off after it overheats??

 

[Chris1956]

Trim switches in the throttle handle are usually replaceable. Their wires usually need to go around the throttle pivot, and can rub. Maybe the insulation rubbed off and made a connection between the up and power wires?

Look for a couple of screws on the throttle arm, and a cover plate.

Actually if you go on the crowleymarine web site and look under accessories for your engine make and year, it may have a source for a new switch, and a picture of the control disassembly.

 

[southstar]

Trim switches in the throttle handle are usually replaceable. Their wires usually need to go around the throttle pivot, and can rub. Maybe the insulation rubbed off and made a connection between the up and power wires?

Look for a couple of screws on the throttle arm, and a cover plate.

Actually if you go on the crowleymarine web site and look under accessories for your engine make and year, it may have a source for a new switch, and a picture of the control disassembly.

Chris. It's been a while for me to resolve my problem with the trim stuck in up position. I eventually isolated the trim switch to the one on the throttle by disconnecting the thumb switch on the engine. With the key on and the accessories switch on, the thumb switch on the throttle worked fine!!! Ordered a new switch for the engine and all is good!!! Evidently when I throttled down in rough water, the wake splashed up on the back of the boat and some water got it the trim switch on the engine. Thanks again for your help. BTW that was a sealed switch, and I couldn't blow it out.