99 yamaha 150 hp trim wants to go up by itself

[ermess]

boat will be running and motor on its own will start trimming up out of water. Can hit down button and it will go down, but sometimes it tries to go up even after you put it down.<br />Thanks<br />Ed

 

[rodbolt]

Re: 99 yamaha 150 hp trim wants to go up by itself

thats a tough one to isolate but usually its a trim relay going bad. <br /> post the model number of the motor. and is this a single or twin installation and side mount or binnicle ?

 

[ermess]

Re: 99 yamaha 150 hp trim wants to go up by itself

Single Installation with side mount. Switch on side mount seems real sensitive

 

[rodbolt]

Re: 99 yamaha 150 hp trim wants to go up by itself

next time it happens immediatly disconnect the red lead in the thre wire trim harness . its the group of red,light green and light blue wire at the control box. have them prepositioned. if it quits trimming when you disconnect power at the trim switch you can assume its a bad switch. also try operating it with the pan switch disconnected as that switch can fail as well.<br /> if it still randomy trims up it may well be a bad trim solinoid.<br /> but as you refuse to give the model number I cant tell what ya have so I really cant assist.

 

[swanny]

Re: 99 yamaha 150 hp trim wants to go up by itself

i'm a little late but, had this problem. i had a tilt/trim on my throttle and one in the bow. the switch in the bow was going bad and would trim my motor down on its own. changed the bow switch and corrected the problem.