I'm a first time boat owner with a rough boat. I have a 1973 Webbcraft with a mercruiser 188 hp I/O. My first problem is the trim/tilt. It will tilt down but will not go back up. It is an older switch and the top two buttons don't work but the bottom (IN) button moves the outboard down. I have checked fuses and all connections, is there something I am overlooking because I actually have no idea of what I'm looking for. Could it be the trim pump? please help!! More will be needed