I have a 70hp merc serial#6382744. I went over the entire electrical system on the power trim. The limit switch that stops you from over trimming was all corroded up. I fixed that and It went up to a certain point and then the pump shut off. I hit the trailer button and then it continues all the way up. The problem is I can't find the limit switches that prevent the motor from crushing the transom when it goes down or all the way up. The pump continues to run and I actually bent the removable pin when I was out in the water because I trimmed it to far down. Is it possible that this is how this system works? Any input would be helpful.