I have a 2005 50hp Mercury with about 35 hours on it. Yesterday we went trough some shallow water running with the engine trimmed up quite a bit. (It won't stay up beyond a certain point). This morning I went out to find the power trim motor running unattended and the engine in full up position. As soon as I touched the trim button it quit, whereupon I lowered the unit. I quickly charged the battery to be safe and reinstalled it. As I walked around on the boat it shook it a bit and activated the power trim to raise the engine. It fully raised and refused to shut off until I touched the trim button again. I lowered it once more and it sat perfectly until I reached over and "bounced" it a bit causing the same reaction. Any ideas anyone. I haven't called my favored "Guru" as yet.