Tilt and Trim Problem

I have a 1997 150 yamaha 2 stroke. We went on the boat yesterday and everything was fine. We trailered it home......with the motor up by mistake, and when i was washing it, i could hear the tilt going on its own every 5 minutes or so. The motor was not moving, because it was fully up, but you could here the tilt motor running and turning off, this happened for a while, when I would try to put the motor down, using the switch on the motor, it would not go on. I did the same on the using the switch on the throttle and i got nothing! Mean while it was going on and off by itself ! So I unhooked the battery, negative first then the positve, so I wouldnt ruin the battery. I went out later to see what I could do, I hooked the battery back up......positive first, then when I went to put the negative back on, I got a LOT OF SPARK from the negative, which has NEVER happened before and the tilt came on RIGHT away by its self! So as of now the battery is still unhooked, because I was worried about that spark! The engine will not come down with either switches, and I going off on its own, when the battery is hooked up! Can anyone help!!

[boats.net]

Disconnect 10 pin main electrical harness at motor to eliminate trim switch in boat, connect battery cables and try again.
If still trims disconnect trim switch on motor, try again.

Ok I will try that! It seems easy enough if thats the case.....bad switch......it that hard to change or costly?

Would that make the battery spark like that too?

[jb123]

it may arc if you have a bad batt commection.