Ok I think I may have an understanding... I think either your trim sensor is broke or stuck. That spring, by the looks of the direction it is hooked on the arm, it should be pushing that arm in the up position (clockwise) to be resting on another part of the outboard that moves when adjusting the trim. You can try to spray a bit of lube on it and try to manually get it moving again or replace. You never did mention if you have a trim gauge on your dash. If you dont, I wouldnt worry about it. I dont think a trim gauge is really necessary. If I had a gauge and it didnt work,,, it would bug the hell out of me until it all worked as intended.
