Motor trimming by itself

[Mfoley312]

Hello,

I am a first time boat owner and have had my bass tracker txw 175 for about 6 months now. It has a 50 hp mercury 2 stroke engine. Last night it was pouring down rain, I have my boat in the driveway with a cover on the boat and motor (no garage or standalone garage to keep it under). But at about 1 am the motor was trimming up by itself and it freaked me out, because if I was going to have a problem with the boat I assumed it would have been on the water. But I've been reading that the switch is bad for the trim pump and my question is, how can I tell which switch it is, because I have 3 (one on the motor itself, one of throttle, and one on bow next to trolling motor. Is there a way to test each or will have I to replace one at a time?

 

[GA_Boater]

If the trim pump is still running continuously - The switches are wired in parallel, so disconnecting one at a time will ID the bad switch unless one of the relays decided to short out.

 

[Mfoley312]

It's not constant, but every 20 minutes or so it'll run for about a minute. The trim down was working on the motor switch, but after trimming it down once, it will only work on throttle or bow switch. Does that confirm the motor switch?

If so, do I replace the whole switch? Is there a way to repair/correct it without replacing it?

I'm new to this, sorry for dumb questions.

 

[Chris1956]

I would look at the throttle handle and bow switch switch first. They tend to be the least sealed.

 

[Mfoley312]

Yes, it was the bow switch! There was a tiny bit of water in the around the connectors. Must've shorted it. Will probably just unplug for now and fix when I get a chance.
Thanks for y'alls help!