Trim limit switch is bad. It is located on the side of the gimbal ring on the outside transom assembly.
It is there to prevent you from raising the drive to far when operating the boat. The trailer button bypasses it to raise the drive all the way.
I would leave it be until it's time to replace the bellows as the wires are way back there.
Look and you will probably see the wires are broken off the switch that looks like a round puck.
1997 2400 SCR
5.7 Vortec / Bravo 2